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.
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.
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.
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)