This query should help you out:
SELECT
ic.relname AS index_name,
bc.relname AS tab_name,
ta.attname AS column_name,
i.indisunique AS unique_key,
i.indisprimary AS primary_key
FROM
pg_class bc,
pg_class ic,
pg_index i,
pg_attribute ta,
pg_attribute ia
WHERE
bc.oid = i.indrelid
AND ic.oid = i.indexrelid
AND ia.attrelid = i.indexrelid
AND ta.attrelid = bc.oid
AND bc.relname = '[table_name]'
AND ta.attrelid = i.indrelid
AND ta.attnum = i.indkey[ia.attnum-1]
ORDER BY
index_name, tab_name, column_name
Of course, be sure to change the "[table_name]". Then all you have to do is
check if primary_key is 't' and then get the column name.
-Dan
Quoting Kevin Gordon <kgordon@paradise.net.nz>:
> Question for pqsql-php mail list:
> How can I determine the names of the columns that make up the primary
> key in a postgresql table?
> Your help would be appreciated.
