How do I get the primary key(s) of a table from Postgres via plpgsql?

sql postgresql plpgsql
jsight picture jsight · Jul 31, 2009 · Viewed 65.2k times · Source

Given a table name, how do I extract a list of primary key columns and their datatypes from a plpgsql function?

Answer

user3094383 picture user3094383 · Dec 12, 2013

The query above is very bad as it is really slow.

I would recommend this official version:

http://wiki.postgresql.org/wiki/Retrieve_primary_key_columns

if schema is needed the query is as follows

SELECT               
  pg_attribute.attname, 
  format_type(pg_attribute.atttypid, pg_attribute.atttypmod) 
FROM pg_index, pg_class, pg_attribute, pg_namespace 
WHERE 
  pg_class.oid = 'foo'::regclass AND 
  indrelid = pg_class.oid AND 
  nspname = 'public' AND 
  pg_class.relnamespace = pg_namespace.oid AND 
  pg_attribute.attrelid = pg_class.oid AND 
  pg_attribute.attnum = any(pg_index.indkey)
 AND indisprimary

Related questions

PostgreSQL IF statement

How can I do such query in Postgres? IF (select count(*) from orders) > 0 THEN DELETE from orders ELSE INSERT INTO orders values (1,2,3);

Read More
How to return result of a SELECT inside a function in PostgreSQL?

I have this function in PostgreSQL, but I don't know how to return the result of the query: CREATE OR REPLACE FUNCTION wordFrequency(maxTokens INTEGER) RETURNS SETOF RECORD AS $$ BEGIN SELECT text, count(*), 100 / maxTokens * count(*) FROM ( SELECT text FROM token …

Read More
Return multiple fields as a record in PostgreSQL with PL/pgSQL

I am writing a SP, using PL/pgSQL. I want to return a record, comprised of fields from several different tables. Could look something like this: CREATE OR REPLACE FUNCTION get_object_fields(name text) RETURNS RECORD AS $$ BEGIN -- …

Read More