dblink_get

dblink_get_pkey
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dblink_get_pkey

dblink_get_pkey — returns the positions and field names of a relation's + primary key fields +

Synopsis

+dblink_get_pkey(text relname) returns setof dblink_pkey_results
+

Description

+ dblink_get_pkey provides information about the primary + key of a relation in the local database. This is sometimes useful + in generating queries to be sent to remote databases. +

Arguments

relname: + Name of a local relation, for example foo or + myschema.mytab. Include double quotes if the + name is mixed-case or contains special characters, for + example "FooBar"; without quotes, the string + will be folded to lower case. +

Return Value

+ Returns one row for each primary key field, or no rows if the relation + has no primary key. The result row type is defined as + +

+CREATE TYPE dblink_pkey_results AS (position int, colname text);
+

+ + The position column simply runs from 1 to N; + it is the number of the field within the primary key, not the number + within the table's columns. +

Examples

+CREATE TABLE foobar (
+    f1 int,
+    f2 int,
+    f3 int,
+    PRIMARY KEY (f1, f2, f3)
+);
+CREATE TABLE
+
+SELECT * FROM dblink_get_pkey('foobar');
+ position | colname
+----------+---------
+        1 | f1
+        2 | f2
+        3 | f3
+(3 rows)
+