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|
--
-- TEXT
--
SELECT text 'this is a text string' = text 'this is a text string' AS true;
true
------
t
(1 row)
SELECT text 'this is a text string' = text 'this is a text strin' AS false;
false
-------
f
(1 row)
CREATE TABLE TEXT_TBL (f1 text);
INSERT INTO TEXT_TBL VALUES ('doh!');
INSERT INTO TEXT_TBL VALUES ('hi de ho neighbor');
SELECT '' AS two, * FROM TEXT_TBL;
two | f1
-----+-------------------
| doh!
| hi de ho neighbor
(2 rows)
-- As of 8.3 we have removed most implicit casts to text, so that for example
-- this no longer works:
select length(42);
ERROR: function length(integer) does not exist
LINE 1: select length(42);
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
-- But as a special exception for usability's sake, we still allow implicit
-- casting to text in concatenations, so long as the other input is text or
-- an unknown literal. So these work:
select 'four: '::text || 2+2;
?column?
----------
four: 4
(1 row)
select 'four: ' || 2+2;
?column?
----------
four: 4
(1 row)
-- but not this:
select 3 || 4.0;
ERROR: operator does not exist: integer || numeric
LINE 1: select 3 || 4.0;
^
HINT: No operator matches the given name and argument types. You might need to add explicit type casts.
/*
* various string functions
*/
select concat('one');
concat
--------
one
(1 row)
select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
concat
----------------------
123hellotf03-09-2010
(1 row)
select concat_ws('#','one');
concat_ws
-----------
one
(1 row)
select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
concat_ws
----------------------------
1#2#3#hello#t#f#03-09-2010
(1 row)
select concat_ws(',',10,20,null,30);
concat_ws
-----------
10,20,30
(1 row)
select concat_ws('',10,20,null,30);
concat_ws
-----------
102030
(1 row)
select concat_ws(NULL,10,20,null,30) is null;
?column?
----------
t
(1 row)
select reverse('abcde');
reverse
---------
edcba
(1 row)
select i, left('ahoj', i), right('ahoj', i) from generate_series(-5, 5) t(i) order by i;
i | left | right
----+------+-------
-5 | |
-4 | |
-3 | a | j
-2 | ah | oj
-1 | aho | hoj
0 | |
1 | a | j
2 | ah | oj
3 | aho | hoj
4 | ahoj | ahoj
5 | ahoj | ahoj
(11 rows)
select quote_literal('');
quote_literal
---------------
''
(1 row)
select quote_literal('abc''');
quote_literal
---------------
'abc'''
(1 row)
select quote_literal(e'\\');
quote_literal
---------------
E'\\'
(1 row)
-- check variadic labeled argument
select concat(variadic array[1,2,3]);
concat
--------
123
(1 row)
select concat_ws(',', variadic array[1,2,3]);
concat_ws
-----------
1,2,3
(1 row)
select concat_ws(',', variadic NULL::int[]);
concat_ws
-----------
(1 row)
select concat(variadic NULL::int[]) is NULL;
?column?
----------
t
(1 row)
select concat(variadic '{}'::int[]) = '';
?column?
----------
t
(1 row)
--should fail
select concat_ws(',', variadic 10);
ERROR: VARIADIC argument must be an array
LINE 1: select concat_ws(',', variadic 10);
^
/*
* format
*/
select format(NULL);
format
--------
(1 row)
select format('Hello');
format
--------
Hello
(1 row)
select format('Hello %s', 'World');
format
-------------
Hello World
(1 row)
select format('Hello %%');
format
---------
Hello %
(1 row)
select format('Hello %%%%');
format
----------
Hello %%
(1 row)
-- should fail
select format('Hello %s %s', 'World');
ERROR: too few arguments for format()
select format('Hello %s');
ERROR: too few arguments for format()
select format('Hello %x', 20);
ERROR: unrecognized format() type specifier "x"
HINT: For a single "%" use "%%".
-- check literal and sql identifiers
select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', 10, 'Hello');
format
----------------------------------------
INSERT INTO mytab VALUES('10','Hello')
(1 row)
select format('%s%s%s','Hello', NULL,'World');
format
------------
HelloWorld
(1 row)
select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', 10, NULL);
format
-------------------------------------
INSERT INTO mytab VALUES('10',NULL)
(1 row)
select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', NULL, 'Hello');
format
----------------------------------------
INSERT INTO mytab VALUES(NULL,'Hello')
(1 row)
-- should fail, sql identifier cannot be NULL
select format('INSERT INTO %I VALUES(%L,%L)', NULL, 10, 'Hello');
ERROR: null values cannot be formatted as an SQL identifier
-- check positional placeholders
select format('%1$s %3$s', 1, 2, 3);
format
--------
1 3
(1 row)
select format('%1$s %12$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
format
--------
1 12
(1 row)
-- should fail
select format('%1$s %4$s', 1, 2, 3);
ERROR: too few arguments for format()
select format('%1$s %13$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
ERROR: too few arguments for format()
select format('%0$s', 'Hello');
ERROR: format specifies argument 0, but arguments are numbered from 1
select format('%*0$s', 'Hello');
ERROR: format specifies argument 0, but arguments are numbered from 1
select format('%1$', 1);
ERROR: unterminated format() type specifier
HINT: For a single "%" use "%%".
select format('%1$1', 1);
ERROR: unterminated format() type specifier
HINT: For a single "%" use "%%".
-- check mix of positional and ordered placeholders
select format('Hello %s %1$s %s', 'World', 'Hello again');
format
-------------------------------
Hello World World Hello again
(1 row)
select format('Hello %s %s, %2$s %2$s', 'World', 'Hello again');
format
--------------------------------------------------
Hello World Hello again, Hello again Hello again
(1 row)
-- check variadic labeled arguments
select format('%s, %s', variadic array['Hello','World']);
format
--------------
Hello, World
(1 row)
select format('%s, %s', variadic array[1, 2]);
format
--------
1, 2
(1 row)
select format('%s, %s', variadic array[true, false]);
format
--------
t, f
(1 row)
select format('%s, %s', variadic array[true, false]::text[]);
format
-------------
true, false
(1 row)
-- check variadic with positional placeholders
select format('%2$s, %1$s', variadic array['first', 'second']);
format
---------------
second, first
(1 row)
select format('%2$s, %1$s', variadic array[1, 2]);
format
--------
2, 1
(1 row)
-- variadic argument can be array type NULL, but should not be referenced
select format('Hello', variadic NULL::int[]);
format
--------
Hello
(1 row)
-- variadic argument allows simulating more than FUNC_MAX_ARGS parameters
select format(string_agg('%s',','), variadic array_agg(i))
from generate_series(1,200) g(i);
format
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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
(1 row)
-- check field widths and left, right alignment
select format('>>%10s<<', 'Hello');
format
----------------
>> Hello<<
(1 row)
select format('>>%10s<<', NULL);
format
----------------
>> <<
(1 row)
select format('>>%10s<<', '');
format
----------------
>> <<
(1 row)
select format('>>%-10s<<', '');
format
----------------
>> <<
(1 row)
select format('>>%-10s<<', 'Hello');
format
----------------
>>Hello <<
(1 row)
select format('>>%-10s<<', NULL);
format
----------------
>> <<
(1 row)
select format('>>%1$10s<<', 'Hello');
format
----------------
>> Hello<<
(1 row)
select format('>>%1$-10I<<', 'Hello');
format
----------------
>>"Hello" <<
(1 row)
select format('>>%2$*1$L<<', 10, 'Hello');
format
----------------
>> 'Hello'<<
(1 row)
select format('>>%2$*1$L<<', 10, NULL);
format
----------------
>> NULL<<
(1 row)
select format('>>%2$*1$L<<', -10, NULL);
format
----------------
>>NULL <<
(1 row)
select format('>>%*s<<', 10, 'Hello');
format
----------------
>> Hello<<
(1 row)
select format('>>%*1$s<<', 10, 'Hello');
format
----------------
>> Hello<<
(1 row)
select format('>>%-s<<', 'Hello');
format
-----------
>>Hello<<
(1 row)
select format('>>%10L<<', NULL);
format
----------------
>> NULL<<
(1 row)
select format('>>%2$*1$L<<', NULL, 'Hello');
format
-------------
>>'Hello'<<
(1 row)
select format('>>%2$*1$L<<', 0, 'Hello');
format
-------------
>>'Hello'<<
(1 row)
|