Postgresql: how to create table only if it does not already exist?

Question

In Postgresql, how can I do a condition to create a table only if it does not already exist?

Code example appreciated.

Answer 1

The best answer has been given by Skalli if you're running Postgresql 9.1+.

If like me you need to do that with Postgresql 8.4, you can use a function with a 'duplicate_table' exception catch.

This will ignore the generated error when the table exists and keep generating other errors.

Here is an example working on Postgresql 8.4.10 :

CREATE FUNCTION create_table() RETURNS VOID AS
$$
BEGIN
    CREATE TABLE my_table_name(my_column INT);
EXCEPTION WHEN duplicate_table THEN
    -- Do nothing
END;
$$
LANGUAGE plpgsql;