PostgreSQL 8.4.12 Documentation
Prev | Fast Backward |  | Fast Forward | Next

# dblink_get_pkey

## Name

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 rowtype is defined as

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

## Example

    test=# create table foobar(f1 int, f2 int, f3 int,
    test(#   primary key(f1,f2,f3));
    CREATE TABLE
    test=# select * from dblink_get_pkey('foobar');
     position | colname
    ----------+---------
            1 | f1
            2 | f2
            3 | f3
    (3 rows)

Prev | Home | Next
dblink_cancel_query | Up | dblink_build_sql_insert