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Asked: 2026-05-27T02:39:22+00:00

I’m trying to write a command that will delete all functions in a namespace.

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I’m trying to write a command that will delete all functions in a namespace. I’ve already found a command that will generate the drop functions script:

SELECT 'DROP FUNCTION ' || ns.nspname || '.' || proname || '('
     || oidvectortypes(proargtypes) || ');'
FROM pg_proc INNER JOIN pg_namespace ns ON (pg_proc.pronamespace = ns.oid)
WHERE ns.nspname = 'public'  order by proname;

Source: http://www.postgresonline.com/journal/archives/74-How-to-delete-many-functions.html

This will generate something like:

                 ?column?                 
------------------------------------------
 DROP FUNCTION public.function1(bigint);
 DROP FUNCTION public.function2();
 DROP FUNCTION public.function3(text);

However, I can’t figure out how to change the code, so that the functions are actually deleted – as opposed to only generating the commands.

Any ideas?

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1 Answer

  1. Editorial Team

    The system catalogs changed in Postgres 11! (prokind instead of proisagg) See:

    Could look like this:

    CREATE OR REPLACE FUNCTION public.f_delfunc(_schema text, _del text = '')
  RETURNS text AS
$func$
DECLARE
   _sql   text;
   _ct    text;
BEGIN
   SELECT INTO _sql, _ct
          string_agg('DROP '
                   || CASE p.proisagg WHEN true THEN 'AGGREGATE '
                                                ELSE 'FUNCTION ' END
                   || quote_ident(n.nspname) || '.' || quote_ident(p.proname)
                   || '('
                   || pg_catalog.pg_get_function_identity_arguments(p.oid)
                   || ')'
                    , E'\n'
          )
          ,count(*)::text
   FROM   pg_catalog.pg_proc p
   LEFT   JOIN pg_catalog.pg_namespace n ON n.oid = p.pronamespace
   WHERE  n.nspname = _schema;
   -- AND p.proname ~~* 'f_%';                     -- Only selected funcs?
   -- AND pg_catalog.pg_function_is_visible(p.oid) -- Only visible funcs?

   IF _ct = '0' THEN
      RETURN 'Found 0 functions to delete';
   ELSIF lower(_del) = 'del' THEN                        -- Actually delete!
      EXECUTE _sql;
      RETURN _ct || E' functions deleted:\n' || _sql;
   ELSE                                               -- Else only show SQL.
      RETURN _ct || E' functions to delete:\n' || _sql;
   END IF;
END
$func$  LANGUAGE plpgsql;

    Call to show:

    SELECT f_delfunc('public');         -- 2nd parameter is covered by default.

    Call to delete:

    SELECT f_delfunc('public','del');

    Major points

    • You need dynamic SQL for that. Use a plpgsql function or a DO statement (PostgreSQL 9.0+) with EXECUTE.

    • Note the use of the functions pg_get_function_identity_arguments() and pg_function_is_visible. The latter can be omitted. It’s a safeguard so you don’t delete functions outside of the current user’s search_path.

    • I added a “safe mode”. Only delete if $2 = 'del'. Else only show generated SQL.

    • Be aware that the function will delete itself if it lives in the schema you delete from.

    • I also added quote_ident() to safeguard against SQLi. Consider the following:

    CREATE FUNCTION "; DELETE FROM users;"()
  RETURNS int AS
'SELECT 1'
  LANGUAGE sql;
    • This fails if there are dependencies on any involved function. May be resolved by adding CASCADE, but I did not do that here, since it makes the function more dangerous, yet.

    Related:

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