-- Name: check_constraint_canon_sql(check_constraint_def); Type: FUNCTION; Schema: util; Owner: -

--

CREATE FUNCTION check_constraint_canon_sql(def check_constraint_def) RETURNS text

    LANGUAGE plpgsql STRICT

    AS $$

-- must be declared STRICT to handle NULL properly

/* **IMPORTANT**: must be declared VOLATILE to be able to see concurrent

modifications to system catalogs */

DECLARE

	result text;

	table_ regclass = (def).constraint_.table_;

	temp_table text = util.qual_name('pg_temp', util.name(table_));

	temp_constraint_def util.check_constraint_def;

BEGIN

	BEGIN

		-- use empty temp table so don't try to run constraint on all rows

		PERFORM util.copy_struct(table_, temp_table);

		-- now that table's regclass exists

		temp_constraint_def = ((temp_table, (def).constraint_.name), def.expr);

		PERFORM util.check_constraint_replace(temp_constraint_def,

			canon := false/*avoid infinite recursion*/);

		result = util.check_constraint_expr(temp_constraint_def.constraint_);

		-- delete temp tables

		PERFORM util.raise('ROLBK', 'sandbox block finished and rolled back');

	EXCEPTION

	WHEN SQLSTATE 'ROLBK' THEN NULL;

	END;

	RETURN result;

END;

$$;

--

-- Name: FUNCTION check_constraint_canon_sql(def check_constraint_def); Type: COMMENT; Schema: util; Owner: -

--

COMMENT ON FUNCTION check_constraint_canon_sql(def check_constraint_def) IS '

**WARNING**: this must be used instead of plain util.canon_sql() because unlike

queries, CHECK constraints are not simplified, just standardized

';

--