# 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