views:

456

answers:

2

Hello.

I have a name of table or view in PostgreSQL database and need to delete in in single pgSQL command. How can i afford it?

I was able to select form system table to find out if there any table with such a name but stuck with procedural part:

SELECT count(*) FROM pg_tables where tablename='user_statistics';
+4  A: 
DROP TABLE user_statistics;

DROP VIEW user_statistics;

complete syntax:

DROP TABLE

DROP VIEW

And if you want a complete function, i tried something like this:

CREATE OR REPLACE FUNCTION delete_table_or_view(objectName varchar) RETURNS integer AS $$
DECLARE
    isTable integer;
    isView integer;
BEGIN
    SELECT INTO isTable count(*) FROM pg_tables where tablename=objectName;
    SELECT INTO isView count(*) FROM pg_views where viewname=objectName;

    IF isTable = 1 THEN
     execute 'DROP TABLE ' || objectName;
     RETURN 1;
    END IF;

    IF isView = 1 THEN
     execute 'DROP VIEW ' || objectName;
     RETURN 2;
    END IF;

    RETURN 0;

END;
$$ LANGUAGE plpgsql;
empi
+1  A: 

Consider using DROP TABLE IF EXISTS and DROP VIEW IF EXISTS. That way you won't get an error message if it fails, just a notice.

Magnus Hagander
That won't work actually. If you're doing `DROP VIEW IF EXISTS` and the view that you are trying to drop is actually a table than Postgres will give you an error that it is not a view (the same goes for `DROP TABLE IF EXISTS`). You need to know for sure if it's a table or a view.
WoLpH