dblink_get_pkey — returns the positions and field names of a relation's primary key fields
dblink_get_pkey(text relname) returns setof dblink_pkey_results
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.
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.
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)