CREATE OR REPLACE FUNCTION public.create_plpgsql_language ()
        RETURNS TEXT
        AS $$
            CREATE LANGUAGE plpgsql;
            SELECT 'language plpgsql created'::TEXT;
        $$
LANGUAGE 'sql';

SELECT CASE WHEN
              (SELECT true::BOOLEAN
                 FROM pg_language
                WHERE lanname='plpgsql')
            THEN
              (SELECT 'language already installed'::TEXT)
            ELSE
              (SELECT public.create_plpgsql_language())
            END;
DROP FUNCTION public.create_plpgsql_language ();
