1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>9.16. JSON Functions and Operators</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="functions-xml.html" title="9.15. XML Functions" /><link rel="next" href="functions-sequence.html" title="9.17. Sequence Manipulation Functions" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">9.16. JSON Functions and Operators</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="functions-xml.html" title="9.15. XML Functions">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="functions.html" title="Chapter 9. Functions and Operators">Up</a></td><th width="60%" align="center">Chapter 9. Functions and Operators</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="functions-sequence.html" title="9.17. Sequence Manipulation Functions">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="FUNCTIONS-JSON"><div class="titlepage"><div><div><h2 class="title" style="clear: both">9.16. JSON Functions and Operators</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="functions-json.html#FUNCTIONS-JSON-PROCESSING">9.16.1. Processing and Creating JSON Data</a></span></dt><dt><span class="sect2"><a href="functions-json.html#FUNCTIONS-SQLJSON-PATH">9.16.2. The SQL/JSON Path Language</a></span></dt></dl></div><a id="id-1.5.8.22.2" class="indexterm"></a><p>
This section describes:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
functions and operators for processing and creating JSON data
</p></li><li class="listitem"><p>
the SQL/JSON path language
</p></li></ul></div><p>
</p><p>
To learn more about the SQL/JSON standard, see
<a class="xref" href="biblio.html#SQLTR-19075-6" title="SQL Technical Report">[sqltr-19075-6]</a>. For details on JSON types
supported in <span class="productname">PostgreSQL</span>,
see <a class="xref" href="datatype-json.html" title="8.14. JSON Types">Section 8.14</a>.
</p><div class="sect2" id="FUNCTIONS-JSON-PROCESSING"><div class="titlepage"><div><div><h3 class="title">9.16.1. Processing and Creating JSON Data</h3></div></div></div><p>
<a class="xref" href="functions-json.html#FUNCTIONS-JSON-OP-TABLE" title="Table 9.44. json and jsonb Operators">Table 9.44</a> shows the operators that
are available for use with JSON data types (see <a class="xref" href="datatype-json.html" title="8.14. JSON Types">Section 8.14</a>).
In addition, the usual comparison operators shown in <a class="xref" href="functions-comparison.html#FUNCTIONS-COMPARISON-OP-TABLE" title="Table 9.1. Comparison Operators">Table 9.1</a> are available for
<code class="type">jsonb</code>, though not for <code class="type">json</code>. The comparison
operators follow the ordering rules for B-tree operations outlined in
<a class="xref" href="datatype-json.html#JSON-INDEXING" title="8.14.4. jsonb Indexing">Section 8.14.4</a>.
</p><div class="table" id="FUNCTIONS-JSON-OP-TABLE"><p class="title"><strong>Table 9.44. <code class="type">json</code> and <code class="type">jsonb</code> Operators</strong></p><div class="table-contents"><table class="table" summary="json and jsonb Operators" border="1"><colgroup><col /></colgroup><thead><tr><th class="func_table_entry"><p class="func_signature">
Operator
</p>
<p>
Description
</p>
<p>
Example(s)
</p></th></tr></thead><tbody><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">json</code> <code class="literal">-></code> <code class="type">integer</code>
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<code class="type">jsonb</code> <code class="literal">-></code> <code class="type">integer</code>
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Extracts <em class="parameter"><code>n</code></em>'th element of JSON array
(array elements are indexed from zero, but negative integers count
from the end).
</p>
<p>
<code class="literal">'[{"a":"foo"},{"b":"bar"},{"c":"baz"}]'::json -> 2</code>
→ <code class="returnvalue">{"c":"baz"}</code>
</p>
<p>
<code class="literal">'[{"a":"foo"},{"b":"bar"},{"c":"baz"}]'::json -> -3</code>
→ <code class="returnvalue">{"a":"foo"}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">json</code> <code class="literal">-></code> <code class="type">text</code>
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<code class="type">jsonb</code> <code class="literal">-></code> <code class="type">text</code>
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Extracts JSON object field with the given key.
</p>
<p>
<code class="literal">'{"a": {"b":"foo"}}'::json -> 'a'</code>
→ <code class="returnvalue">{"b":"foo"}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">json</code> <code class="literal">->></code> <code class="type">integer</code>
→ <code class="returnvalue">text</code>
</p>
<p class="func_signature">
<code class="type">jsonb</code> <code class="literal">->></code> <code class="type">integer</code>
→ <code class="returnvalue">text</code>
</p>
<p>
Extracts <em class="parameter"><code>n</code></em>'th element of JSON array,
as <code class="type">text</code>.
</p>
<p>
<code class="literal">'[1,2,3]'::json ->> 2</code>
→ <code class="returnvalue">3</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">json</code> <code class="literal">->></code> <code class="type">text</code>
→ <code class="returnvalue">text</code>
</p>
<p class="func_signature">
<code class="type">jsonb</code> <code class="literal">->></code> <code class="type">text</code>
→ <code class="returnvalue">text</code>
</p>
<p>
Extracts JSON object field with the given key, as <code class="type">text</code>.
</p>
<p>
<code class="literal">'{"a":1,"b":2}'::json ->> 'b'</code>
→ <code class="returnvalue">2</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">json</code> <code class="literal">#></code> <code class="type">text[]</code>
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<code class="type">jsonb</code> <code class="literal">#></code> <code class="type">text[]</code>
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Extracts JSON sub-object at the specified path, where path elements
can be either field keys or array indexes.
</p>
<p>
<code class="literal">'{"a": {"b": ["foo","bar"]}}'::json #> '{a,b,1}'</code>
→ <code class="returnvalue">"bar"</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">json</code> <code class="literal">#>></code> <code class="type">text[]</code>
→ <code class="returnvalue">text</code>
</p>
<p class="func_signature">
<code class="type">jsonb</code> <code class="literal">#>></code> <code class="type">text[]</code>
→ <code class="returnvalue">text</code>
</p>
<p>
Extracts JSON sub-object at the specified path as <code class="type">text</code>.
</p>
<p>
<code class="literal">'{"a": {"b": ["foo","bar"]}}'::json #>> '{a,b,1}'</code>
→ <code class="returnvalue">bar</code>
</p></td></tr></tbody></table></div></div><br class="table-break" /><div class="note"><h3 class="title">Note</h3><p>
The field/element/path extraction operators return NULL, rather than
failing, if the JSON input does not have the right structure to match
the request; for example if no such key or array element exists.
</p></div><p>
Some further operators exist only for <code class="type">jsonb</code>, as shown
in <a class="xref" href="functions-json.html#FUNCTIONS-JSONB-OP-TABLE" title="Table 9.45. Additional jsonb Operators">Table 9.45</a>.
<a class="xref" href="datatype-json.html#JSON-INDEXING" title="8.14.4. jsonb Indexing">Section 8.14.4</a>
describes how these operators can be used to effectively search indexed
<code class="type">jsonb</code> data.
</p><div class="table" id="FUNCTIONS-JSONB-OP-TABLE"><p class="title"><strong>Table 9.45. Additional <code class="type">jsonb</code> Operators</strong></p><div class="table-contents"><table class="table" summary="Additional jsonb Operators" border="1"><colgroup><col /></colgroup><thead><tr><th class="func_table_entry"><p class="func_signature">
Operator
</p>
<p>
Description
</p>
<p>
Example(s)
</p></th></tr></thead><tbody><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">@></code> <code class="type">jsonb</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Does the first JSON value contain the second?
(See <a class="xref" href="datatype-json.html#JSON-CONTAINMENT" title="8.14.3. jsonb Containment and Existence">Section 8.14.3</a> for details about containment.)
</p>
<p>
<code class="literal">'{"a":1, "b":2}'::jsonb @> '{"b":2}'::jsonb</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal"><@</code> <code class="type">jsonb</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Is the first JSON value contained in the second?
</p>
<p>
<code class="literal">'{"b":2}'::jsonb <@ '{"a":1, "b":2}'::jsonb</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">?</code> <code class="type">text</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Does the text string exist as a top-level key or array element within
the JSON value?
</p>
<p>
<code class="literal">'{"a":1, "b":2}'::jsonb ? 'b'</code>
→ <code class="returnvalue">t</code>
</p>
<p>
<code class="literal">'["a", "b", "c"]'::jsonb ? 'b'</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">?|</code> <code class="type">text[]</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Do any of the strings in the text array exist as top-level keys or
array elements?
</p>
<p>
<code class="literal">'{"a":1, "b":2, "c":3}'::jsonb ?| array['b', 'd']</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">?&</code> <code class="type">text[]</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Do all of the strings in the text array exist as top-level keys or
array elements?
</p>
<p>
<code class="literal">'["a", "b", "c"]'::jsonb ?& array['a', 'b']</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">||</code> <code class="type">jsonb</code>
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Concatenates two <code class="type">jsonb</code> values.
Concatenating two arrays generates an array containing all the
elements of each input. Concatenating two objects generates an
object containing the union of their
keys, taking the second object's value when there are duplicate keys.
All other cases are treated by converting a non-array input into a
single-element array, and then proceeding as for two arrays.
Does not operate recursively: only the top-level array or object
structure is merged.
</p>
<p>
<code class="literal">'["a", "b"]'::jsonb || '["a", "d"]'::jsonb</code>
→ <code class="returnvalue">["a", "b", "a", "d"]</code>
</p>
<p>
<code class="literal">'{"a": "b"}'::jsonb || '{"c": "d"}'::jsonb</code>
→ <code class="returnvalue">{"a": "b", "c": "d"}</code>
</p>
<p>
<code class="literal">'[1, 2]'::jsonb || '3'::jsonb</code>
→ <code class="returnvalue">[1, 2, 3]</code>
</p>
<p>
<code class="literal">'{"a": "b"}'::jsonb || '42'::jsonb</code>
→ <code class="returnvalue">[{"a": "b"}, 42]</code>
</p>
<p>
To append an array to another array as a single entry, wrap it
in an additional layer of array, for example:
</p>
<p>
<code class="literal">'[1, 2]'::jsonb || jsonb_build_array('[3, 4]'::jsonb)</code>
→ <code class="returnvalue">[1, 2, [3, 4]]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">-</code> <code class="type">text</code>
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Deletes a key (and its value) from a JSON object, or matching string
value(s) from a JSON array.
</p>
<p>
<code class="literal">'{"a": "b", "c": "d"}'::jsonb - 'a'</code>
→ <code class="returnvalue">{"c": "d"}</code>
</p>
<p>
<code class="literal">'["a", "b", "c", "b"]'::jsonb - 'b'</code>
→ <code class="returnvalue">["a", "c"]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">-</code> <code class="type">text[]</code>
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Deletes all matching keys or array elements from the left operand.
</p>
<p>
<code class="literal">'{"a": "b", "c": "d"}'::jsonb - '{a,c}'::text[]</code>
→ <code class="returnvalue">{}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">-</code> <code class="type">integer</code>
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Deletes the array element with specified index (negative
integers count from the end). Throws an error if JSON value
is not an array.
</p>
<p>
<code class="literal">'["a", "b"]'::jsonb - 1 </code>
→ <code class="returnvalue">["a"]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">#-</code> <code class="type">text[]</code>
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Deletes the field or array element at the specified path, where path
elements can be either field keys or array indexes.
</p>
<p>
<code class="literal">'["a", {"b":1}]'::jsonb #- '{1,b}'</code>
→ <code class="returnvalue">["a", {}]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">@?</code> <code class="type">jsonpath</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Does JSON path return any item for the specified JSON value?
</p>
<p>
<code class="literal">'{"a":[1,2,3,4,5]}'::jsonb @? '$.a[*] ? (@ > 2)'</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="type">jsonb</code> <code class="literal">@@</code> <code class="type">jsonpath</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Returns the result of a JSON path predicate check for the
specified JSON value. Only the first item of the result is taken into
account. If the result is not Boolean, then <code class="literal">NULL</code>
is returned.
</p>
<p>
<code class="literal">'{"a":[1,2,3,4,5]}'::jsonb @@ '$.a[*] > 2'</code>
→ <code class="returnvalue">t</code>
</p></td></tr></tbody></table></div></div><br class="table-break" /><div class="note"><h3 class="title">Note</h3><p>
The <code class="type">jsonpath</code> operators <code class="literal">@?</code>
and <code class="literal">@@</code> suppress the following errors: missing object
field or array element, unexpected JSON item type, datetime and numeric
errors. The <code class="type">jsonpath</code>-related functions described below can
also be told to suppress these types of errors. This behavior might be
helpful when searching JSON document collections of varying structure.
</p></div><p>
<a class="xref" href="functions-json.html#FUNCTIONS-JSON-CREATION-TABLE" title="Table 9.46. JSON Creation Functions">Table 9.46</a> shows the functions that are
available for constructing <code class="type">json</code> and <code class="type">jsonb</code> values.
</p><div class="table" id="FUNCTIONS-JSON-CREATION-TABLE"><p class="title"><strong>Table 9.46. JSON Creation Functions</strong></p><div class="table-contents"><table class="table" summary="JSON Creation Functions" border="1"><colgroup><col /></colgroup><thead><tr><th class="func_table_entry"><p class="func_signature">
Function
</p>
<p>
Description
</p>
<p>
Example(s)
</p></th></tr></thead><tbody><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.1.1.1.1" class="indexterm"></a>
<code class="function">to_json</code> ( <code class="type">anyelement</code> )
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.1.1.2.1" class="indexterm"></a>
<code class="function">to_jsonb</code> ( <code class="type">anyelement</code> )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Converts any SQL value to <code class="type">json</code> or <code class="type">jsonb</code>.
Arrays and composites are converted recursively to arrays and
objects (multidimensional arrays become arrays of arrays in JSON).
Otherwise, if there is a cast from the SQL data type
to <code class="type">json</code>, the cast function will be used to perform the
conversion;<a href="#ftn.id-1.5.8.22.5.9.2.2.1.1.3.4" class="footnote"><sup class="footnote" id="id-1.5.8.22.5.9.2.2.1.1.3.4">[a]</sup></a>
otherwise, a scalar JSON value is produced. For any scalar other than
a number, a Boolean, or a null value, the text representation will be
used, with escaping as necessary to make it a valid JSON string value.
</p>
<p>
<code class="literal">to_json('Fred said "Hi."'::text)</code>
→ <code class="returnvalue">"Fred said \"Hi.\""</code>
</p>
<p>
<code class="literal">to_jsonb(row(42, 'Fred said "Hi."'::text))</code>
→ <code class="returnvalue">{"f1": 42, "f2": "Fred said \"Hi.\""}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.2.1.1.1" class="indexterm"></a>
<code class="function">array_to_json</code> ( <code class="type">anyarray</code> [<span class="optional">, <code class="type">boolean</code> </span>] )
→ <code class="returnvalue">json</code>
</p>
<p>
Converts an SQL array to a JSON array. The behavior is the same
as <code class="function">to_json</code> except that line feeds will be added
between top-level array elements if the optional boolean parameter is
true.
</p>
<p>
<code class="literal">array_to_json('{{1,5},{99,100}}'::int[])</code>
→ <code class="returnvalue">[[1,5],[99,100]]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.3.1.1.1" class="indexterm"></a>
<code class="function">row_to_json</code> ( <code class="type">record</code> [<span class="optional">, <code class="type">boolean</code> </span>] )
→ <code class="returnvalue">json</code>
</p>
<p>
Converts an SQL composite value to a JSON object. The behavior is the
same as <code class="function">to_json</code> except that line feeds will be
added between top-level elements if the optional boolean parameter is
true.
</p>
<p>
<code class="literal">row_to_json(row(1,'foo'))</code>
→ <code class="returnvalue">{"f1":1,"f2":"foo"}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.4.1.1.1" class="indexterm"></a>
<code class="function">json_build_array</code> ( <code class="literal">VARIADIC</code> <code class="type">"any"</code> )
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.4.1.2.1" class="indexterm"></a>
<code class="function">jsonb_build_array</code> ( <code class="literal">VARIADIC</code> <code class="type">"any"</code> )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Builds a possibly-heterogeneously-typed JSON array out of a variadic
argument list. Each argument is converted as
per <code class="function">to_json</code> or <code class="function">to_jsonb</code>.
</p>
<p>
<code class="literal">json_build_array(1, 2, 'foo', 4, 5)</code>
→ <code class="returnvalue">[1, 2, "foo", 4, 5]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.5.1.1.1" class="indexterm"></a>
<code class="function">json_build_object</code> ( <code class="literal">VARIADIC</code> <code class="type">"any"</code> )
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.5.1.2.1" class="indexterm"></a>
<code class="function">jsonb_build_object</code> ( <code class="literal">VARIADIC</code> <code class="type">"any"</code> )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Builds a JSON object out of a variadic argument list. By convention,
the argument list consists of alternating keys and values. Key
arguments are coerced to text; value arguments are converted as
per <code class="function">to_json</code> or <code class="function">to_jsonb</code>.
</p>
<p>
<code class="literal">json_build_object('foo', 1, 2, row(3,'bar'))</code>
→ <code class="returnvalue">{"foo" : 1, "2" : {"f1":3,"f2":"bar"}}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.6.1.1.1" class="indexterm"></a>
<code class="function">json_object</code> ( <code class="type">text[]</code> )
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.9.2.2.6.1.2.1" class="indexterm"></a>
<code class="function">jsonb_object</code> ( <code class="type">text[]</code> )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Builds a JSON object out of a text array. The array must have either
exactly one dimension with an even number of members, in which case
they are taken as alternating key/value pairs, or two dimensions
such that each inner array has exactly two elements, which
are taken as a key/value pair. All values are converted to JSON
strings.
</p>
<p>
<code class="literal">json_object('{a, 1, b, "def", c, 3.5}')</code>
→ <code class="returnvalue">{"a" : "1", "b" : "def", "c" : "3.5"}</code>
</p>
<p><code class="literal">json_object('{{a, 1}, {b, "def"}, {c, 3.5}}')</code>
→ <code class="returnvalue">{"a" : "1", "b" : "def", "c" : "3.5"}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="function">json_object</code> ( <em class="parameter"><code>keys</code></em> <code class="type">text[]</code>, <em class="parameter"><code>values</code></em> <code class="type">text[]</code> )
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<code class="function">jsonb_object</code> ( <em class="parameter"><code>keys</code></em> <code class="type">text[]</code>, <em class="parameter"><code>values</code></em> <code class="type">text[]</code> )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
This form of <code class="function">json_object</code> takes keys and values
pairwise from separate text arrays. Otherwise it is identical to
the one-argument form.
</p>
<p>
<code class="literal">json_object('{a,b}', '{1,2}')</code>
→ <code class="returnvalue">{"a": "1", "b": "2"}</code>
</p></td></tr></tbody><tbody class="footnotes"><tr><td colspan="1"><div id="ftn.id-1.5.8.22.5.9.2.2.1.1.3.4" class="footnote"><p><a href="#id-1.5.8.22.5.9.2.2.1.1.3.4" class="para"><sup class="para">[a] </sup></a>
For example, the <a class="xref" href="hstore.html" title="F.16. hstore">hstore</a> extension has a cast
from <code class="type">hstore</code> to <code class="type">json</code>, so that
<code class="type">hstore</code> values converted via the JSON creation functions
will be represented as JSON objects, not as primitive string values.
</p></div></td></tr></tbody></table></div></div><br class="table-break" /><p>
<a class="xref" href="functions-json.html#FUNCTIONS-JSON-PROCESSING-TABLE" title="Table 9.47. JSON Processing Functions">Table 9.47</a> shows the functions that
are available for processing <code class="type">json</code> and <code class="type">jsonb</code> values.
</p><div class="table" id="FUNCTIONS-JSON-PROCESSING-TABLE"><p class="title"><strong>Table 9.47. JSON Processing Functions</strong></p><div class="table-contents"><table class="table" summary="JSON Processing Functions" border="1"><colgroup><col /></colgroup><thead><tr><th class="func_table_entry"><p class="func_signature">
Function
</p>
<p>
Description
</p>
<p>
Example(s)
</p></th></tr></thead><tbody><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.1.1.1.1" class="indexterm"></a>
<code class="function">json_array_elements</code> ( <code class="type">json</code> )
→ <code class="returnvalue">setof json</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.1.1.2.1" class="indexterm"></a>
<code class="function">jsonb_array_elements</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">setof jsonb</code>
</p>
<p>
Expands the top-level JSON array into a set of JSON values.
</p>
<p>
<code class="literal">select * from json_array_elements('[1,true, [2,false]]')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
value
-----------
1
true
[2,false]
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.2.1.1.1" class="indexterm"></a>
<code class="function">json_array_elements_text</code> ( <code class="type">json</code> )
→ <code class="returnvalue">setof text</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.2.1.2.1" class="indexterm"></a>
<code class="function">jsonb_array_elements_text</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">setof text</code>
</p>
<p>
Expands the top-level JSON array into a set of <code class="type">text</code> values.
</p>
<p>
<code class="literal">select * from json_array_elements_text('["foo", "bar"]')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
value
-----------
foo
bar
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.3.1.1.1" class="indexterm"></a>
<code class="function">json_array_length</code> ( <code class="type">json</code> )
→ <code class="returnvalue">integer</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.3.1.2.1" class="indexterm"></a>
<code class="function">jsonb_array_length</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">integer</code>
</p>
<p>
Returns the number of elements in the top-level JSON array.
</p>
<p>
<code class="literal">json_array_length('[1,2,3,{"f1":1,"f2":[5,6]},4]')</code>
→ <code class="returnvalue">5</code>
</p>
<p>
<code class="literal">jsonb_array_length('[]')</code>
→ <code class="returnvalue">0</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.4.1.1.1" class="indexterm"></a>
<code class="function">json_each</code> ( <code class="type">json</code> )
→ <code class="returnvalue">setof record</code>
( <em class="parameter"><code>key</code></em> <code class="type">text</code>,
<em class="parameter"><code>value</code></em> <code class="type">json</code> )
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.4.1.2.1" class="indexterm"></a>
<code class="function">jsonb_each</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">setof record</code>
( <em class="parameter"><code>key</code></em> <code class="type">text</code>,
<em class="parameter"><code>value</code></em> <code class="type">jsonb</code> )
</p>
<p>
Expands the top-level JSON object into a set of key/value pairs.
</p>
<p>
<code class="literal">select * from json_each('{"a":"foo", "b":"bar"}')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
key | value
-----+-------
a | "foo"
b | "bar"
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.5.1.1.1" class="indexterm"></a>
<code class="function">json_each_text</code> ( <code class="type">json</code> )
→ <code class="returnvalue">setof record</code>
( <em class="parameter"><code>key</code></em> <code class="type">text</code>,
<em class="parameter"><code>value</code></em> <code class="type">text</code> )
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.5.1.2.1" class="indexterm"></a>
<code class="function">jsonb_each_text</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">setof record</code>
( <em class="parameter"><code>key</code></em> <code class="type">text</code>,
<em class="parameter"><code>value</code></em> <code class="type">text</code> )
</p>
<p>
Expands the top-level JSON object into a set of key/value pairs.
The returned <em class="parameter"><code>value</code></em>s will be of
type <code class="type">text</code>.
</p>
<p>
<code class="literal">select * from json_each_text('{"a":"foo", "b":"bar"}')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
key | value
-----+-------
a | foo
b | bar
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.6.1.1.1" class="indexterm"></a>
<code class="function">json_extract_path</code> ( <em class="parameter"><code>from_json</code></em> <code class="type">json</code>, <code class="literal">VARIADIC</code> <em class="parameter"><code>path_elems</code></em> <code class="type">text[]</code> )
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.6.1.2.1" class="indexterm"></a>
<code class="function">jsonb_extract_path</code> ( <em class="parameter"><code>from_json</code></em> <code class="type">jsonb</code>, <code class="literal">VARIADIC</code> <em class="parameter"><code>path_elems</code></em> <code class="type">text[]</code> )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Extracts JSON sub-object at the specified path.
(This is functionally equivalent to the <code class="literal">#></code>
operator, but writing the path out as a variadic list can be more
convenient in some cases.)
</p>
<p>
<code class="literal">json_extract_path('{"f2":{"f3":1},"f4":{"f5":99,"f6":"foo"}}', 'f4', 'f6')</code>
→ <code class="returnvalue">"foo"</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.7.1.1.1" class="indexterm"></a>
<code class="function">json_extract_path_text</code> ( <em class="parameter"><code>from_json</code></em> <code class="type">json</code>, <code class="literal">VARIADIC</code> <em class="parameter"><code>path_elems</code></em> <code class="type">text[]</code> )
→ <code class="returnvalue">text</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.7.1.2.1" class="indexterm"></a>
<code class="function">jsonb_extract_path_text</code> ( <em class="parameter"><code>from_json</code></em> <code class="type">jsonb</code>, <code class="literal">VARIADIC</code> <em class="parameter"><code>path_elems</code></em> <code class="type">text[]</code> )
→ <code class="returnvalue">text</code>
</p>
<p>
Extracts JSON sub-object at the specified path as <code class="type">text</code>.
(This is functionally equivalent to the <code class="literal">#>></code>
operator.)
</p>
<p>
<code class="literal">json_extract_path_text('{"f2":{"f3":1},"f4":{"f5":99,"f6":"foo"}}', 'f4', 'f6')</code>
→ <code class="returnvalue">foo</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.8.1.1.1" class="indexterm"></a>
<code class="function">json_object_keys</code> ( <code class="type">json</code> )
→ <code class="returnvalue">setof text</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.8.1.2.1" class="indexterm"></a>
<code class="function">jsonb_object_keys</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">setof text</code>
</p>
<p>
Returns the set of keys in the top-level JSON object.
</p>
<p>
<code class="literal">select * from json_object_keys('{"f1":"abc","f2":{"f3":"a", "f4":"b"}}')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
json_object_keys
------------------
f1
f2
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.9.1.1.1" class="indexterm"></a>
<code class="function">json_populate_record</code> ( <em class="parameter"><code>base</code></em> <code class="type">anyelement</code>, <em class="parameter"><code>from_json</code></em> <code class="type">json</code> )
→ <code class="returnvalue">anyelement</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.9.1.2.1" class="indexterm"></a>
<code class="function">jsonb_populate_record</code> ( <em class="parameter"><code>base</code></em> <code class="type">anyelement</code>, <em class="parameter"><code>from_json</code></em> <code class="type">jsonb</code> )
→ <code class="returnvalue">anyelement</code>
</p>
<p>
Expands the top-level JSON object to a row having the composite type
of the <em class="parameter"><code>base</code></em> argument. The JSON object
is scanned for fields whose names match column names of the output row
type, and their values are inserted into those columns of the output.
(Fields that do not correspond to any output column name are ignored.)
In typical use, the value of <em class="parameter"><code>base</code></em> is just
<code class="literal">NULL</code>, which means that any output columns that do
not match any object field will be filled with nulls. However,
if <em class="parameter"><code>base</code></em> isn't <code class="literal">NULL</code> then
the values it contains will be used for unmatched columns.
</p>
<p>
To convert a JSON value to the SQL type of an output column, the
following rules are applied in sequence:
</p><div class="itemizedlist"><ul class="itemizedlist compact" style="list-style-type: disc; "><li class="listitem"><p>
A JSON null value is converted to an SQL null in all cases.
</p></li><li class="listitem"><p>
If the output column is of type <code class="type">json</code>
or <code class="type">jsonb</code>, the JSON value is just reproduced exactly.
</p></li><li class="listitem"><p>
If the output column is a composite (row) type, and the JSON value
is a JSON object, the fields of the object are converted to columns
of the output row type by recursive application of these rules.
</p></li><li class="listitem"><p>
Likewise, if the output column is an array type and the JSON value
is a JSON array, the elements of the JSON array are converted to
elements of the output array by recursive application of these
rules.
</p></li><li class="listitem"><p>
Otherwise, if the JSON value is a string, the contents of the
string are fed to the input conversion function for the column's
data type.
</p></li><li class="listitem"><p>
Otherwise, the ordinary text representation of the JSON value is
fed to the input conversion function for the column's data type.
</p></li></ul></div><p>
</p>
<p>
While the example below uses a constant JSON value, typical use would
be to reference a <code class="type">json</code> or <code class="type">jsonb</code> column
laterally from another table in the query's <code class="literal">FROM</code>
clause. Writing <code class="function">json_populate_record</code> in
the <code class="literal">FROM</code> clause is good practice, since all of the
extracted columns are available for use without duplicate function
calls.
</p>
<p>
<code class="literal">create type subrowtype as (d int, e text);</code>
<code class="literal">create type myrowtype as (a int, b text[], c subrowtype);</code>
</p>
<p>
<code class="literal">select * from json_populate_record(null::myrowtype,
'{"a": 1, "b": ["2", "a b"], "c": {"d": 4, "e": "a b c"}, "x": "foo"}')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
a | b | c
---+-----------+-------------
1 | {2,"a b"} | (4,"a b c")
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.10.1.1.1" class="indexterm"></a>
<code class="function">json_populate_recordset</code> ( <em class="parameter"><code>base</code></em> <code class="type">anyelement</code>, <em class="parameter"><code>from_json</code></em> <code class="type">json</code> )
→ <code class="returnvalue">setof anyelement</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.10.1.2.1" class="indexterm"></a>
<code class="function">jsonb_populate_recordset</code> ( <em class="parameter"><code>base</code></em> <code class="type">anyelement</code>, <em class="parameter"><code>from_json</code></em> <code class="type">jsonb</code> )
→ <code class="returnvalue">setof anyelement</code>
</p>
<p>
Expands the top-level JSON array of objects to a set of rows having
the composite type of the <em class="parameter"><code>base</code></em> argument.
Each element of the JSON array is processed as described above
for <code class="function">json[b]_populate_record</code>.
</p>
<p>
<code class="literal">create type twoints as (a int, b int);</code>
</p>
<p>
<code class="literal">select * from json_populate_recordset(null::twoints, '[{"a":1,"b":2}, {"a":3,"b":4}]')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
a | b
---+---
1 | 2
3 | 4
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.11.1.1.1" class="indexterm"></a>
<code class="function">json_to_record</code> ( <code class="type">json</code> )
→ <code class="returnvalue">record</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.11.1.2.1" class="indexterm"></a>
<code class="function">jsonb_to_record</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">record</code>
</p>
<p>
Expands the top-level JSON object to a row having the composite type
defined by an <code class="literal">AS</code> clause. (As with all functions
returning <code class="type">record</code>, the calling query must explicitly
define the structure of the record with an <code class="literal">AS</code>
clause.) The output record is filled from fields of the JSON object,
in the same way as described above
for <code class="function">json[b]_populate_record</code>. Since there is no
input record value, unmatched columns are always filled with nulls.
</p>
<p>
<code class="literal">create type myrowtype as (a int, b text);</code>
</p>
<p>
<code class="literal">select * from json_to_record('{"a":1,"b":[1,2,3],"c":[1,2,3],"e":"bar","r": {"a": 123, "b": "a b c"}}') as x(a int, b text, c int[], d text, r myrowtype)</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
a | b | c | d | r
---+---------+---------+---+---------------
1 | [1,2,3] | {1,2,3} | | (123,"a b c")
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.12.1.1.1" class="indexterm"></a>
<code class="function">json_to_recordset</code> ( <code class="type">json</code> )
→ <code class="returnvalue">setof record</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.12.1.2.1" class="indexterm"></a>
<code class="function">jsonb_to_recordset</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">setof record</code>
</p>
<p>
Expands the top-level JSON array of objects to a set of rows having
the composite type defined by an <code class="literal">AS</code> clause. (As
with all functions returning <code class="type">record</code>, the calling query
must explicitly define the structure of the record with
an <code class="literal">AS</code> clause.) Each element of the JSON array is
processed as described above
for <code class="function">json[b]_populate_record</code>.
</p>
<p>
<code class="literal">select * from json_to_recordset('[{"a":1,"b":"foo"}, {"a":"2","c":"bar"}]') as x(a int, b text)</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
a | b
---+-----
1 | foo
2 |
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.13.1.1.1" class="indexterm"></a>
<code class="function">jsonb_set</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">text[]</code>, <em class="parameter"><code>new_value</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>create_if_missing</code></em> <code class="type">boolean</code> </span>] )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Returns <em class="parameter"><code>target</code></em>
with the item designated by <em class="parameter"><code>path</code></em>
replaced by <em class="parameter"><code>new_value</code></em>, or with
<em class="parameter"><code>new_value</code></em> added if
<em class="parameter"><code>create_if_missing</code></em> is true (which is the
default) and the item designated by <em class="parameter"><code>path</code></em>
does not exist.
All earlier steps in the path must exist, or
the <em class="parameter"><code>target</code></em> is returned unchanged.
As with the path oriented operators, negative integers that
appear in the <em class="parameter"><code>path</code></em> count from the end
of JSON arrays.
If the last path step is an array index that is out of range,
and <em class="parameter"><code>create_if_missing</code></em> is true, the new
value is added at the beginning of the array if the index is negative,
or at the end of the array if it is positive.
</p>
<p>
<code class="literal">jsonb_set('[{"f1":1,"f2":null},2,null,3]', '{0,f1}', '[2,3,4]', false)</code>
→ <code class="returnvalue">[{"f1": [2, 3, 4], "f2": null}, 2, null, 3]</code>
</p>
<p>
<code class="literal">jsonb_set('[{"f1":1,"f2":null},2]', '{0,f3}', '[2,3,4]')</code>
→ <code class="returnvalue">[{"f1": 1, "f2": null, "f3": [2, 3, 4]}, 2]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.14.1.1.1" class="indexterm"></a>
<code class="function">jsonb_set_lax</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">text[]</code>, <em class="parameter"><code>new_value</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>create_if_missing</code></em> <code class="type">boolean</code> [<span class="optional">, <em class="parameter"><code>null_value_treatment</code></em> <code class="type">text</code> </span>]</span>] )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
If <em class="parameter"><code>new_value</code></em> is not <code class="literal">NULL</code>,
behaves identically to <code class="literal">jsonb_set</code>. Otherwise behaves
according to the value
of <em class="parameter"><code>null_value_treatment</code></em> which must be one
of <code class="literal">'raise_exception'</code>,
<code class="literal">'use_json_null'</code>, <code class="literal">'delete_key'</code>, or
<code class="literal">'return_target'</code>. The default is
<code class="literal">'use_json_null'</code>.
</p>
<p>
<code class="literal">jsonb_set_lax('[{"f1":1,"f2":null},2,null,3]', '{0,f1}', null)</code>
→ <code class="returnvalue">[{"f1":null,"f2":null},2,null,3]</code>
</p>
<p>
<code class="literal">jsonb_set_lax('[{"f1":99,"f2":null},2]', '{0,f3}', null, true, 'return_target')</code>
→ <code class="returnvalue">[{"f1": 99, "f2": null}, 2]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.15.1.1.1" class="indexterm"></a>
<code class="function">jsonb_insert</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">text[]</code>, <em class="parameter"><code>new_value</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>insert_after</code></em> <code class="type">boolean</code> </span>] )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Returns <em class="parameter"><code>target</code></em>
with <em class="parameter"><code>new_value</code></em> inserted. If the item
designated by the <em class="parameter"><code>path</code></em> is an array
element, <em class="parameter"><code>new_value</code></em> will be inserted before
that item if <em class="parameter"><code>insert_after</code></em> is false (which
is the default), or after it
if <em class="parameter"><code>insert_after</code></em> is true. If the item
designated by the <em class="parameter"><code>path</code></em> is an object
field, <em class="parameter"><code>new_value</code></em> will be inserted only if
the object does not already contain that key.
All earlier steps in the path must exist, or
the <em class="parameter"><code>target</code></em> is returned unchanged.
As with the path oriented operators, negative integers that
appear in the <em class="parameter"><code>path</code></em> count from the end
of JSON arrays.
If the last path step is an array index that is out of range, the new
value is added at the beginning of the array if the index is negative,
or at the end of the array if it is positive.
</p>
<p>
<code class="literal">jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"')</code>
→ <code class="returnvalue">{"a": [0, "new_value", 1, 2]}</code>
</p>
<p>
<code class="literal">jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"', true)</code>
→ <code class="returnvalue">{"a": [0, 1, "new_value", 2]}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.16.1.1.1" class="indexterm"></a>
<code class="function">json_strip_nulls</code> ( <code class="type">json</code> )
→ <code class="returnvalue">json</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.16.1.2.1" class="indexterm"></a>
<code class="function">jsonb_strip_nulls</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Deletes all object fields that have null values from the given JSON
value, recursively. Null values that are not object fields are
untouched.
</p>
<p>
<code class="literal">json_strip_nulls('[{"f1":1, "f2":null}, 2, null, 3]')</code>
→ <code class="returnvalue">[{"f1":1},2,null,3]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.17.1.1.1" class="indexterm"></a>
<code class="function">jsonb_path_exists</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">boolean</code>
</p>
<p>
Checks whether the JSON path returns any item for the specified JSON
value.
If the <em class="parameter"><code>vars</code></em> argument is specified, it must
be a JSON object, and its fields provide named values to be
substituted into the <code class="type">jsonpath</code> expression.
If the <em class="parameter"><code>silent</code></em> argument is specified and
is <code class="literal">true</code>, the function suppresses the same errors
as the <code class="literal">@?</code> and <code class="literal">@@</code> operators do.
</p>
<p>
<code class="literal">jsonb_path_exists('{"a":[1,2,3,4,5]}', '$.a[*] ? (@ >= $min && @ <= $max)', '{"min":2, "max":4}')</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.18.1.1.1" class="indexterm"></a>
<code class="function">jsonb_path_match</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">boolean</code>
</p>
<p>
Returns the result of a JSON path predicate check for the specified
JSON value. Only the first item of the result is taken into account.
If the result is not Boolean, then <code class="literal">NULL</code> is returned.
The optional <em class="parameter"><code>vars</code></em>
and <em class="parameter"><code>silent</code></em> arguments act the same as
for <code class="function">jsonb_path_exists</code>.
</p>
<p>
<code class="literal">jsonb_path_match('{"a":[1,2,3,4,5]}', 'exists($.a[*] ? (@ >= $min && @ <= $max))', '{"min":2, "max":4}')</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.19.1.1.1" class="indexterm"></a>
<code class="function">jsonb_path_query</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">setof jsonb</code>
</p>
<p>
Returns all JSON items returned by the JSON path for the specified
JSON value.
The optional <em class="parameter"><code>vars</code></em>
and <em class="parameter"><code>silent</code></em> arguments act the same as
for <code class="function">jsonb_path_exists</code>.
</p>
<p>
<code class="literal">select * from jsonb_path_query('{"a":[1,2,3,4,5]}', '$.a[*] ? (@ >= $min && @ <= $max)', '{"min":2, "max":4}')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
jsonb_path_query
------------------
2
3
4
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.20.1.1.1" class="indexterm"></a>
<code class="function">jsonb_path_query_array</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Returns all JSON items returned by the JSON path for the specified
JSON value, as a JSON array.
The optional <em class="parameter"><code>vars</code></em>
and <em class="parameter"><code>silent</code></em> arguments act the same as
for <code class="function">jsonb_path_exists</code>.
</p>
<p>
<code class="literal">jsonb_path_query_array('{"a":[1,2,3,4,5]}', '$.a[*] ? (@ >= $min && @ <= $max)', '{"min":2, "max":4}')</code>
→ <code class="returnvalue">[2, 3, 4]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.21.1.1.1" class="indexterm"></a>
<code class="function">jsonb_path_query_first</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
Returns the first JSON item returned by the JSON path for the
specified JSON value. Returns <code class="literal">NULL</code> if there are no
results.
The optional <em class="parameter"><code>vars</code></em>
and <em class="parameter"><code>silent</code></em> arguments act the same as
for <code class="function">jsonb_path_exists</code>.
</p>
<p>
<code class="literal">jsonb_path_query_first('{"a":[1,2,3,4,5]}', '$.a[*] ? (@ >= $min && @ <= $max)', '{"min":2, "max":4}')</code>
→ <code class="returnvalue">2</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.22.1.1.1" class="indexterm"></a>
<code class="function">jsonb_path_exists_tz</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">boolean</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.22.1.2.1" class="indexterm"></a>
<code class="function">jsonb_path_match_tz</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">boolean</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.22.1.3.1" class="indexterm"></a>
<code class="function">jsonb_path_query_tz</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">setof jsonb</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.22.1.4.1" class="indexterm"></a>
<code class="function">jsonb_path_query_array_tz</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">jsonb</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.22.1.5.1" class="indexterm"></a>
<code class="function">jsonb_path_query_first_tz</code> ( <em class="parameter"><code>target</code></em> <code class="type">jsonb</code>, <em class="parameter"><code>path</code></em> <code class="type">jsonpath</code> [<span class="optional">, <em class="parameter"><code>vars</code></em> <code class="type">jsonb</code> [<span class="optional">, <em class="parameter"><code>silent</code></em> <code class="type">boolean</code> </span>]</span>] )
→ <code class="returnvalue">jsonb</code>
</p>
<p>
These functions act like their counterparts described above without
the <code class="literal">_tz</code> suffix, except that these functions support
comparisons of date/time values that require timezone-aware
conversions. The example below requires interpretation of the
date-only value <code class="literal">2015-08-02</code> as a timestamp with time
zone, so the result depends on the current
<a class="xref" href="runtime-config-client.html#GUC-TIMEZONE">TimeZone</a> setting. Due to this dependency, these
functions are marked as stable, which means these functions cannot be
used in indexes. Their counterparts are immutable, and so can be used
in indexes; but they will throw errors if asked to make such
comparisons.
</p>
<p>
<code class="literal">jsonb_path_exists_tz('["2015-08-01 12:00:00 -05"]', '$[*] ? (@.datetime() < "2015-08-02".datetime())')</code>
→ <code class="returnvalue">t</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.23.1.1.1" class="indexterm"></a>
<code class="function">jsonb_pretty</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">text</code>
</p>
<p>
Converts the given JSON value to pretty-printed, indented text.
</p>
<p>
<code class="literal">jsonb_pretty('[{"f1":1,"f2":null}, 2]')</code>
→ <code class="returnvalue"></code>
</p><pre class="programlisting">
[
{
"f1": 1,
"f2": null
},
2
]
</pre><p>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.24.1.1.1" class="indexterm"></a>
<code class="function">json_typeof</code> ( <code class="type">json</code> )
→ <code class="returnvalue">text</code>
</p>
<p class="func_signature">
<a id="id-1.5.8.22.5.11.2.2.24.1.2.1" class="indexterm"></a>
<code class="function">jsonb_typeof</code> ( <code class="type">jsonb</code> )
→ <code class="returnvalue">text</code>
</p>
<p>
Returns the type of the top-level JSON value as a text string.
Possible types are
<code class="literal">object</code>, <code class="literal">array</code>,
<code class="literal">string</code>, <code class="literal">number</code>,
<code class="literal">boolean</code>, and <code class="literal">null</code>.
(The <code class="literal">null</code> result should not be confused
with an SQL NULL; see the examples.)
</p>
<p>
<code class="literal">json_typeof('-123.4')</code>
→ <code class="returnvalue">number</code>
</p>
<p>
<code class="literal">json_typeof('null'::json)</code>
→ <code class="returnvalue">null</code>
</p>
<p>
<code class="literal">json_typeof(NULL::json) IS NULL</code>
→ <code class="returnvalue">t</code>
</p></td></tr></tbody></table></div></div><br class="table-break" /><p>
See also <a class="xref" href="functions-aggregate.html" title="9.21. Aggregate Functions">Section 9.21</a> for the aggregate
function <code class="function">json_agg</code> which aggregates record
values as JSON, the aggregate function
<code class="function">json_object_agg</code> which aggregates pairs of values
into a JSON object, and their <code class="type">jsonb</code> equivalents,
<code class="function">jsonb_agg</code> and <code class="function">jsonb_object_agg</code>.
</p></div><div class="sect2" id="FUNCTIONS-SQLJSON-PATH"><div class="titlepage"><div><div><h3 class="title">9.16.2. The SQL/JSON Path Language</h3></div></div></div><a id="id-1.5.8.22.6.2" class="indexterm"></a><p>
SQL/JSON path expressions specify the items to be retrieved
from the JSON data, similar to XPath expressions used
for SQL access to XML. In <span class="productname">PostgreSQL</span>,
path expressions are implemented as the <code class="type">jsonpath</code>
data type and can use any elements described in
<a class="xref" href="datatype-json.html#DATATYPE-JSONPATH" title="8.14.7. jsonpath Type">Section 8.14.7</a>.
</p><p>
JSON query functions and operators
pass the provided path expression to the <em class="firstterm">path engine</em>
for evaluation. If the expression matches the queried JSON data,
the corresponding JSON item, or set of items, is returned.
Path expressions are written in the SQL/JSON path language
and can include arithmetic expressions and functions.
</p><p>
A path expression consists of a sequence of elements allowed
by the <code class="type">jsonpath</code> data type.
The path expression is normally evaluated from left to right, but
you can use parentheses to change the order of operations.
If the evaluation is successful, a sequence of JSON items is produced,
and the evaluation result is returned to the JSON query function
that completes the specified computation.
</p><p>
To refer to the JSON value being queried (the
<em class="firstterm">context item</em>), use the <code class="literal">$</code> variable
in the path expression. It can be followed by one or more
<a class="link" href="datatype-json.html#TYPE-JSONPATH-ACCESSORS" title="Table 8.25. jsonpath Accessors">accessor operators</a>,
which go down the JSON structure level by level to retrieve sub-items
of the context item. Each operator that follows deals with the
result of the previous evaluation step.
</p><p>
For example, suppose you have some JSON data from a GPS tracker that you
would like to parse, such as:
</p><pre class="programlisting">
{
"track": {
"segments": [
{
"location": [ 47.763, 13.4034 ],
"start time": "2018-10-14 10:05:14",
"HR": 73
},
{
"location": [ 47.706, 13.2635 ],
"start time": "2018-10-14 10:39:21",
"HR": 135
}
]
}
}
</pre><p>
</p><p>
To retrieve the available track segments, you need to use the
<code class="literal">.<em class="replaceable"><code>key</code></em></code> accessor
operator to descend through surrounding JSON objects:
</p><pre class="programlisting">
$.track.segments
</pre><p>
</p><p>
To retrieve the contents of an array, you typically use the
<code class="literal">[*]</code> operator. For example,
the following path will return the location coordinates for all
the available track segments:
</p><pre class="programlisting">
$.track.segments[*].location
</pre><p>
</p><p>
To return the coordinates of the first segment only, you can
specify the corresponding subscript in the <code class="literal">[]</code>
accessor operator. Recall that JSON array indexes are 0-relative:
</p><pre class="programlisting">
$.track.segments[0].location
</pre><p>
</p><p>
The result of each path evaluation step can be processed
by one or more <code class="type">jsonpath</code> operators and methods
listed in <a class="xref" href="functions-json.html#FUNCTIONS-SQLJSON-PATH-OPERATORS" title="9.16.2.2. SQL/JSON Path Operators and Methods">Section 9.16.2.2</a>.
Each method name must be preceded by a dot. For example,
you can get the size of an array:
</p><pre class="programlisting">
$.track.segments.size()
</pre><p>
More examples of using <code class="type">jsonpath</code> operators
and methods within path expressions appear below in
<a class="xref" href="functions-json.html#FUNCTIONS-SQLJSON-PATH-OPERATORS" title="9.16.2.2. SQL/JSON Path Operators and Methods">Section 9.16.2.2</a>.
</p><p>
When defining a path, you can also use one or more
<em class="firstterm">filter expressions</em> that work similarly to the
<code class="literal">WHERE</code> clause in SQL. A filter expression begins with
a question mark and provides a condition in parentheses:
</p><pre class="programlisting">
? (<em class="replaceable"><code>condition</code></em>)
</pre><p>
</p><p>
Filter expressions must be written just after the path evaluation step
to which they should apply. The result of that step is filtered to include
only those items that satisfy the provided condition. SQL/JSON defines
three-valued logic, so the condition can be <code class="literal">true</code>, <code class="literal">false</code>,
or <code class="literal">unknown</code>. The <code class="literal">unknown</code> value
plays the same role as SQL <code class="literal">NULL</code> and can be tested
for with the <code class="literal">is unknown</code> predicate. Further path
evaluation steps use only those items for which the filter expression
returned <code class="literal">true</code>.
</p><p>
The functions and operators that can be used in filter expressions are
listed in <a class="xref" href="functions-json.html#FUNCTIONS-SQLJSON-FILTER-EX-TABLE" title="Table 9.49. jsonpath Filter Expression Elements">Table 9.49</a>. Within a
filter expression, the <code class="literal">@</code> variable denotes the value
being filtered (i.e., one result of the preceding path step). You can
write accessor operators after <code class="literal">@</code> to retrieve component
items.
</p><p>
For example, suppose you would like to retrieve all heart rate values higher
than 130. You can achieve this using the following expression:
</p><pre class="programlisting">
$.track.segments[*].HR ? (@ > 130)
</pre><p>
</p><p>
To get the start times of segments with such values, you have to
filter out irrelevant segments before returning the start times, so the
filter expression is applied to the previous step, and the path used
in the condition is different:
</p><pre class="programlisting">
$.track.segments[*] ? (@.HR > 130)."start time"
</pre><p>
</p><p>
You can use several filter expressions in sequence, if required. For
example, the following expression selects start times of all segments that
contain locations with relevant coordinates and high heart rate values:
</p><pre class="programlisting">
$.track.segments[*] ? (@.location[1] < 13.4) ? (@.HR > 130)."start time"
</pre><p>
</p><p>
Using filter expressions at different nesting levels is also allowed.
The following example first filters all segments by location, and then
returns high heart rate values for these segments, if available:
</p><pre class="programlisting">
$.track.segments[*] ? (@.location[1] < 13.4).HR ? (@ > 130)
</pre><p>
</p><p>
You can also nest filter expressions within each other:
</p><pre class="programlisting">
$.track ? (exists(@.segments[*] ? (@.HR > 130))).segments.size()
</pre><p>
This expression returns the size of the track if it contains any
segments with high heart rate values, or an empty sequence otherwise.
</p><p>
<span class="productname">PostgreSQL</span>'s implementation of the SQL/JSON path
language has the following deviations from the SQL/JSON standard:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
A path expression can be a Boolean predicate, although the SQL/JSON
standard allows predicates only in filters. This is necessary for
implementation of the <code class="literal">@@</code> operator. For example,
the following <code class="type">jsonpath</code> expression is valid in
<span class="productname">PostgreSQL</span>:
</p><pre class="programlisting">
$.track.segments[*].HR < 70
</pre><p>
</p></li><li class="listitem"><p>
There are minor differences in the interpretation of regular
expression patterns used in <code class="literal">like_regex</code> filters, as
described in <a class="xref" href="functions-json.html#JSONPATH-REGULAR-EXPRESSIONS" title="9.16.2.3. SQL/JSON Regular Expressions">Section 9.16.2.3</a>.
</p></li></ul></div><div class="sect3" id="STRICT-AND-LAX-MODES"><div class="titlepage"><div><div><h4 class="title">9.16.2.1. Strict and Lax Modes</h4></div></div></div><p>
When you query JSON data, the path expression may not match the
actual JSON data structure. An attempt to access a non-existent
member of an object or element of an array results in a
structural error. SQL/JSON path expressions have two modes
of handling structural errors:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
lax (default) — the path engine implicitly adapts
the queried data to the specified path.
Any remaining structural errors are suppressed and converted
to empty SQL/JSON sequences.
</p></li><li class="listitem"><p>
strict — if a structural error occurs, an error is raised.
</p></li></ul></div><p>
The lax mode facilitates matching of a JSON document structure and path
expression if the JSON data does not conform to the expected schema.
If an operand does not match the requirements of a particular operation,
it can be automatically wrapped as an SQL/JSON array or unwrapped by
converting its elements into an SQL/JSON sequence before performing
this operation. Besides, comparison operators automatically unwrap their
operands in the lax mode, so you can compare SQL/JSON arrays
out-of-the-box. An array of size 1 is considered equal to its sole element.
Automatic unwrapping is not performed only when:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
The path expression contains <code class="literal">type()</code> or
<code class="literal">size()</code> methods that return the type
and the number of elements in the array, respectively.
</p></li><li class="listitem"><p>
The queried JSON data contain nested arrays. In this case, only
the outermost array is unwrapped, while all the inner arrays
remain unchanged. Thus, implicit unwrapping can only go one
level down within each path evaluation step.
</p></li></ul></div><p>
</p><p>
For example, when querying the GPS data listed above, you can
abstract from the fact that it stores an array of segments
when using the lax mode:
</p><pre class="programlisting">
lax $.track.segments.location
</pre><p>
</p><p>
In the strict mode, the specified path must exactly match the structure of
the queried JSON document to return an SQL/JSON item, so using this
path expression will cause an error. To get the same result as in
the lax mode, you have to explicitly unwrap the
<code class="literal">segments</code> array:
</p><pre class="programlisting">
strict $.track.segments[*].location
</pre><p>
</p><p>
The <code class="literal">.**</code> accessor can lead to surprising results
when using the lax mode. For instance, the following query selects every
<code class="literal">HR</code> value twice:
</p><pre class="programlisting">
lax $.**.HR
</pre><p>
This happens because the <code class="literal">.**</code> accessor selects both
the <code class="literal">segments</code> array and each of its elements, while
the <code class="literal">.HR</code> accessor automatically unwraps arrays when
using the lax mode. To avoid surprising results, we recommend using
the <code class="literal">.**</code> accessor only in the strict mode. The
following query selects each <code class="literal">HR</code> value just once:
</p><pre class="programlisting">
strict $.**.HR
</pre><p>
</p></div><div class="sect3" id="FUNCTIONS-SQLJSON-PATH-OPERATORS"><div class="titlepage"><div><div><h4 class="title">9.16.2.2. SQL/JSON Path Operators and Methods</h4></div></div></div><p>
<a class="xref" href="functions-json.html#FUNCTIONS-SQLJSON-OP-TABLE" title="Table 9.48. jsonpath Operators and Methods">Table 9.48</a> shows the operators and
methods available in <code class="type">jsonpath</code>. Note that while the unary
operators and methods can be applied to multiple values resulting from a
preceding path step, the binary operators (addition etc.) can only be
applied to single values.
</p><div class="table" id="FUNCTIONS-SQLJSON-OP-TABLE"><p class="title"><strong>Table 9.48. <code class="type">jsonpath</code> Operators and Methods</strong></p><div class="table-contents"><table class="table" summary="jsonpath Operators and Methods" border="1"><colgroup><col /></colgroup><thead><tr><th class="func_table_entry"><p class="func_signature">
Operator/Method
</p>
<p>
Description
</p>
<p>
Example(s)
</p></th></tr></thead><tbody><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>number</code></em> <code class="literal">+</code> <em class="replaceable"><code>number</code></em>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Addition
</p>
<p>
<code class="literal">jsonb_path_query('[2]', '$[0] + 3')</code>
→ <code class="returnvalue">5</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="literal">+</code> <em class="replaceable"><code>number</code></em>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Unary plus (no operation); unlike addition, this can iterate over
multiple values
</p>
<p>
<code class="literal">jsonb_path_query_array('{"x": [2,3,4]}', '+ $.x')</code>
→ <code class="returnvalue">[2, 3, 4]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>number</code></em> <code class="literal">-</code> <em class="replaceable"><code>number</code></em>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Subtraction
</p>
<p>
<code class="literal">jsonb_path_query('[2]', '7 - $[0]')</code>
→ <code class="returnvalue">5</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="literal">-</code> <em class="replaceable"><code>number</code></em>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Negation; unlike subtraction, this can iterate over
multiple values
</p>
<p>
<code class="literal">jsonb_path_query_array('{"x": [2,3,4]}', '- $.x')</code>
→ <code class="returnvalue">[-2, -3, -4]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>number</code></em> <code class="literal">*</code> <em class="replaceable"><code>number</code></em>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Multiplication
</p>
<p>
<code class="literal">jsonb_path_query('[4]', '2 * $[0]')</code>
→ <code class="returnvalue">8</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>number</code></em> <code class="literal">/</code> <em class="replaceable"><code>number</code></em>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Division
</p>
<p>
<code class="literal">jsonb_path_query('[8.5]', '$[0] / 2')</code>
→ <code class="returnvalue">4.2500000000000000</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>number</code></em> <code class="literal">%</code> <em class="replaceable"><code>number</code></em>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Modulo (remainder)
</p>
<p>
<code class="literal">jsonb_path_query('[32]', '$[0] % 10')</code>
→ <code class="returnvalue">2</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal">.</code> <code class="literal">type()</code>
→ <code class="returnvalue"><em class="replaceable"><code>string</code></em></code>
</p>
<p>
Type of the JSON item (see <code class="function">json_typeof</code>)
</p>
<p>
<code class="literal">jsonb_path_query_array('[1, "2", {}]', '$[*].type()')</code>
→ <code class="returnvalue">["number", "string", "object"]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal">.</code> <code class="literal">size()</code>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Size of the JSON item (number of array elements, or 1 if not an
array)
</p>
<p>
<code class="literal">jsonb_path_query('{"m": [11, 15]}', '$.m.size()')</code>
→ <code class="returnvalue">2</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal">.</code> <code class="literal">double()</code>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Approximate floating-point number converted from a JSON number or
string
</p>
<p>
<code class="literal">jsonb_path_query('{"len": "1.9"}', '$.len.double() * 2')</code>
→ <code class="returnvalue">3.8</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>number</code></em> <code class="literal">.</code> <code class="literal">ceiling()</code>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Nearest integer greater than or equal to the given number
</p>
<p>
<code class="literal">jsonb_path_query('{"h": 1.3}', '$.h.ceiling()')</code>
→ <code class="returnvalue">2</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>number</code></em> <code class="literal">.</code> <code class="literal">floor()</code>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Nearest integer less than or equal to the given number
</p>
<p>
<code class="literal">jsonb_path_query('{"h": 1.7}', '$.h.floor()')</code>
→ <code class="returnvalue">1</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>number</code></em> <code class="literal">.</code> <code class="literal">abs()</code>
→ <code class="returnvalue"><em class="replaceable"><code>number</code></em></code>
</p>
<p>
Absolute value of the given number
</p>
<p>
<code class="literal">jsonb_path_query('{"z": -0.3}', '$.z.abs()')</code>
→ <code class="returnvalue">0.3</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>string</code></em> <code class="literal">.</code> <code class="literal">datetime()</code>
→ <code class="returnvalue"><em class="replaceable"><code>datetime_type</code></em></code>
(see note)
</p>
<p>
Date/time value converted from a string
</p>
<p>
<code class="literal">jsonb_path_query('["2015-8-1", "2015-08-12"]', '$[*] ? (@.datetime() < "2015-08-2".datetime())')</code>
→ <code class="returnvalue">"2015-8-1"</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>string</code></em> <code class="literal">.</code> <code class="literal">datetime(<em class="replaceable"><code>template</code></em>)</code>
→ <code class="returnvalue"><em class="replaceable"><code>datetime_type</code></em></code>
(see note)
</p>
<p>
Date/time value converted from a string using the
specified <code class="function">to_timestamp</code> template
</p>
<p>
<code class="literal">jsonb_path_query_array('["12:30", "18:40"]', '$[*].datetime("HH24:MI")')</code>
→ <code class="returnvalue">["12:30:00", "18:40:00"]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>object</code></em> <code class="literal">.</code> <code class="literal">keyvalue()</code>
→ <code class="returnvalue"><em class="replaceable"><code>array</code></em></code>
</p>
<p>
The object's key-value pairs, represented as an array of objects
containing three fields: <code class="literal">"key"</code>,
<code class="literal">"value"</code>, and <code class="literal">"id"</code>;
<code class="literal">"id"</code> is a unique identifier of the object the
key-value pair belongs to
</p>
<p>
<code class="literal">jsonb_path_query_array('{"x": "20", "y": 32}', '$.keyvalue()')</code>
→ <code class="returnvalue">[{"id": 0, "key": "x", "value": "20"}, {"id": 0, "key": "y", "value": 32}]</code>
</p></td></tr></tbody></table></div></div><br class="table-break" /><div class="note"><h3 class="title">Note</h3><p>
The result type of the <code class="literal">datetime()</code> and
<code class="literal">datetime(<em class="replaceable"><code>template</code></em>)</code>
methods can be <code class="type">date</code>, <code class="type">timetz</code>, <code class="type">time</code>,
<code class="type">timestamptz</code>, or <code class="type">timestamp</code>.
Both methods determine their result type dynamically.
</p><p>
The <code class="literal">datetime()</code> method sequentially tries to
match its input string to the ISO formats
for <code class="type">date</code>, <code class="type">timetz</code>, <code class="type">time</code>,
<code class="type">timestamptz</code>, and <code class="type">timestamp</code>. It stops on
the first matching format and emits the corresponding data type.
</p><p>
The <code class="literal">datetime(<em class="replaceable"><code>template</code></em>)</code>
method determines the result type according to the fields used in the
provided template string.
</p><p>
The <code class="literal">datetime()</code> and
<code class="literal">datetime(<em class="replaceable"><code>template</code></em>)</code> methods
use the same parsing rules as the <code class="literal">to_timestamp</code> SQL
function does (see <a class="xref" href="functions-formatting.html" title="9.8. Data Type Formatting Functions">Section 9.8</a>), with three
exceptions. First, these methods don't allow unmatched template
patterns. Second, only the following separators are allowed in the
template string: minus sign, period, solidus (slash), comma, apostrophe,
semicolon, colon and space. Third, separators in the template string
must exactly match the input string.
</p><p>
If different date/time types need to be compared, an implicit cast is
applied. A <code class="type">date</code> value can be cast to <code class="type">timestamp</code>
or <code class="type">timestamptz</code>, <code class="type">timestamp</code> can be cast to
<code class="type">timestamptz</code>, and <code class="type">time</code> to <code class="type">timetz</code>.
However, all but the first of these conversions depend on the current
<a class="xref" href="runtime-config-client.html#GUC-TIMEZONE">TimeZone</a> setting, and thus can only be performed
within timezone-aware <code class="type">jsonpath</code> functions.
</p></div><p>
<a class="xref" href="functions-json.html#FUNCTIONS-SQLJSON-FILTER-EX-TABLE" title="Table 9.49. jsonpath Filter Expression Elements">Table 9.49</a> shows the available
filter expression elements.
</p><div class="table" id="FUNCTIONS-SQLJSON-FILTER-EX-TABLE"><p class="title"><strong>Table 9.49. <code class="type">jsonpath</code> Filter Expression Elements</strong></p><div class="table-contents"><table class="table" summary="jsonpath Filter Expression Elements" border="1"><colgroup><col /></colgroup><thead><tr><th class="func_table_entry"><p class="func_signature">
Predicate/Value
</p>
<p>
Description
</p>
<p>
Example(s)
</p></th></tr></thead><tbody><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal">==</code> <em class="replaceable"><code>value</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Equality comparison (this, and the other comparison operators, work on
all JSON scalar values)
</p>
<p>
<code class="literal">jsonb_path_query_array('[1, "a", 1, 3]', '$[*] ? (@ == 1)')</code>
→ <code class="returnvalue">[1, 1]</code>
</p>
<p>
<code class="literal">jsonb_path_query_array('[1, "a", 1, 3]', '$[*] ? (@ == "a")')</code>
→ <code class="returnvalue">["a"]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal">!=</code> <em class="replaceable"><code>value</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal"><></code> <em class="replaceable"><code>value</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Non-equality comparison
</p>
<p>
<code class="literal">jsonb_path_query_array('[1, 2, 1, 3]', '$[*] ? (@ != 1)')</code>
→ <code class="returnvalue">[2, 3]</code>
</p>
<p>
<code class="literal">jsonb_path_query_array('["a", "b", "c"]', '$[*] ? (@ <> "b")')</code>
→ <code class="returnvalue">["a", "c"]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal"><</code> <em class="replaceable"><code>value</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Less-than comparison
</p>
<p>
<code class="literal">jsonb_path_query_array('[1, 2, 3]', '$[*] ? (@ < 2)')</code>
→ <code class="returnvalue">[1]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal"><=</code> <em class="replaceable"><code>value</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Less-than-or-equal-to comparison
</p>
<p>
<code class="literal">jsonb_path_query_array('["a", "b", "c"]', '$[*] ? (@ <= "b")')</code>
→ <code class="returnvalue">["a", "b"]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal">></code> <em class="replaceable"><code>value</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Greater-than comparison
</p>
<p>
<code class="literal">jsonb_path_query_array('[1, 2, 3]', '$[*] ? (@ > 2)')</code>
→ <code class="returnvalue">[3]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>value</code></em> <code class="literal">>=</code> <em class="replaceable"><code>value</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Greater-than-or-equal-to comparison
</p>
<p>
<code class="literal">jsonb_path_query_array('[1, 2, 3]', '$[*] ? (@ >= 2)')</code>
→ <code class="returnvalue">[2, 3]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="literal">true</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
JSON constant <code class="literal">true</code>
</p>
<p>
<code class="literal">jsonb_path_query('[{"name": "John", "parent": false}, {"name": "Chris", "parent": true}]', '$[*] ? (@.parent == true)')</code>
→ <code class="returnvalue">{"name": "Chris", "parent": true}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="literal">false</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
JSON constant <code class="literal">false</code>
</p>
<p>
<code class="literal">jsonb_path_query('[{"name": "John", "parent": false}, {"name": "Chris", "parent": true}]', '$[*] ? (@.parent == false)')</code>
→ <code class="returnvalue">{"name": "John", "parent": false}</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="literal">null</code>
→ <code class="returnvalue"><em class="replaceable"><code>value</code></em></code>
</p>
<p>
JSON constant <code class="literal">null</code> (note that, unlike in SQL,
comparison to <code class="literal">null</code> works normally)
</p>
<p>
<code class="literal">jsonb_path_query('[{"name": "Mary", "job": null}, {"name": "Michael", "job": "driver"}]', '$[*] ? (@.job == null) .name')</code>
→ <code class="returnvalue">"Mary"</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>boolean</code></em> <code class="literal">&&</code> <em class="replaceable"><code>boolean</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Boolean AND
</p>
<p>
<code class="literal">jsonb_path_query('[1, 3, 7]', '$[*] ? (@ > 1 && @ < 5)')</code>
→ <code class="returnvalue">3</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>boolean</code></em> <code class="literal">||</code> <em class="replaceable"><code>boolean</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Boolean OR
</p>
<p>
<code class="literal">jsonb_path_query('[1, 3, 7]', '$[*] ? (@ < 1 || @ > 5)')</code>
→ <code class="returnvalue">7</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="literal">!</code> <em class="replaceable"><code>boolean</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Boolean NOT
</p>
<p>
<code class="literal">jsonb_path_query('[1, 3, 7]', '$[*] ? (!(@ < 5))')</code>
→ <code class="returnvalue">7</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>boolean</code></em> <code class="literal">is unknown</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Tests whether a Boolean condition is <code class="literal">unknown</code>.
</p>
<p>
<code class="literal">jsonb_path_query('[-1, 2, 7, "foo"]', '$[*] ? ((@ > 0) is unknown)')</code>
→ <code class="returnvalue">"foo"</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>string</code></em> <code class="literal">like_regex</code> <em class="replaceable"><code>string</code></em> [<span class="optional"> <code class="literal">flag</code> <em class="replaceable"><code>string</code></em> </span>]
→ <code class="returnvalue">boolean</code>
</p>
<p>
Tests whether the first operand matches the regular expression
given by the second operand, optionally with modifications
described by a string of <code class="literal">flag</code> characters (see
<a class="xref" href="functions-json.html#JSONPATH-REGULAR-EXPRESSIONS" title="9.16.2.3. SQL/JSON Regular Expressions">Section 9.16.2.3</a>).
</p>
<p>
<code class="literal">jsonb_path_query_array('["abc", "abd", "aBdC", "abdacb", "babc"]', '$[*] ? (@ like_regex "^ab.*c")')</code>
→ <code class="returnvalue">["abc", "abdacb"]</code>
</p>
<p>
<code class="literal">jsonb_path_query_array('["abc", "abd", "aBdC", "abdacb", "babc"]', '$[*] ? (@ like_regex "^ab.*c" flag "i")')</code>
→ <code class="returnvalue">["abc", "aBdC", "abdacb"]</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<em class="replaceable"><code>string</code></em> <code class="literal">starts with</code> <em class="replaceable"><code>string</code></em>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Tests whether the second operand is an initial substring of the first
operand.
</p>
<p>
<code class="literal">jsonb_path_query('["John Smith", "Mary Stone", "Bob Johnson"]', '$[*] ? (@ starts with "John")')</code>
→ <code class="returnvalue">"John Smith"</code>
</p></td></tr><tr><td class="func_table_entry"><p class="func_signature">
<code class="literal">exists</code> <code class="literal">(</code> <em class="replaceable"><code>path_expression</code></em> <code class="literal">)</code>
→ <code class="returnvalue">boolean</code>
</p>
<p>
Tests whether a path expression matches at least one SQL/JSON item.
Returns <code class="literal">unknown</code> if the path expression would result
in an error; the second example uses this to avoid a no-such-key error
in strict mode.
</p>
<p>
<code class="literal">jsonb_path_query('{"x": [1, 2], "y": [2, 4]}', 'strict $.* ? (exists (@ ? (@[*] > 2)))')</code>
→ <code class="returnvalue">[2, 4]</code>
</p>
<p>
<code class="literal">jsonb_path_query_array('{"value": 41}', 'strict $ ? (exists (@.name)) .name')</code>
→ <code class="returnvalue">[]</code>
</p></td></tr></tbody></table></div></div><br class="table-break" /></div><div class="sect3" id="JSONPATH-REGULAR-EXPRESSIONS"><div class="titlepage"><div><div><h4 class="title">9.16.2.3. SQL/JSON Regular Expressions</h4></div></div></div><a id="id-1.5.8.22.6.24.2" class="indexterm"></a><p>
SQL/JSON path expressions allow matching text to a regular expression
with the <code class="literal">like_regex</code> filter. For example, the
following SQL/JSON path query would case-insensitively match all
strings in an array that start with an English vowel:
</p><pre class="programlisting">
$[*] ? (@ like_regex "^[aeiou]" flag "i")
</pre><p>
</p><p>
The optional <code class="literal">flag</code> string may include one or more of
the characters
<code class="literal">i</code> for case-insensitive match,
<code class="literal">m</code> to allow <code class="literal">^</code>
and <code class="literal">$</code> to match at newlines,
<code class="literal">s</code> to allow <code class="literal">.</code> to match a newline,
and <code class="literal">q</code> to quote the whole pattern (reducing the
behavior to a simple substring match).
</p><p>
The SQL/JSON standard borrows its definition for regular expressions
from the <code class="literal">LIKE_REGEX</code> operator, which in turn uses the
XQuery standard. PostgreSQL does not currently support the
<code class="literal">LIKE_REGEX</code> operator. Therefore,
the <code class="literal">like_regex</code> filter is implemented using the
POSIX regular expression engine described in
<a class="xref" href="functions-matching.html#FUNCTIONS-POSIX-REGEXP" title="9.7.3. POSIX Regular Expressions">Section 9.7.3</a>. This leads to various minor
discrepancies from standard SQL/JSON behavior, which are cataloged in
<a class="xref" href="functions-matching.html#POSIX-VS-XQUERY" title="9.7.3.8. Differences from XQuery (LIKE_REGEX)">Section 9.7.3.8</a>.
Note, however, that the flag-letter incompatibilities described there
do not apply to SQL/JSON, as it translates the XQuery flag letters to
match what the POSIX engine expects.
</p><p>
Keep in mind that the pattern argument of <code class="literal">like_regex</code>
is a JSON path string literal, written according to the rules given in
<a class="xref" href="datatype-json.html#DATATYPE-JSONPATH" title="8.14.7. jsonpath Type">Section 8.14.7</a>. This means in particular that any
backslashes you want to use in the regular expression must be doubled.
For example, to match string values of the root document that contain
only digits:
</p><pre class="programlisting">
$.* ? (@ like_regex "^\\d+$")
</pre><p>
</p></div></div></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="functions-xml.html" title="9.15. XML Functions">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="functions.html" title="Chapter 9. Functions and Operators">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="functions-sequence.html" title="9.17. Sequence Manipulation Functions">Next</a></td></tr><tr><td width="40%" align="left" valign="top">9.15. XML Functions </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 9.17. Sequence Manipulation Functions</td></tr></table></div></body></html>
|
