Help with PostgreSQL constraint

[Xeon SX]

I need to restict adding more than 4 rows to the table.

I tried this but it doesnt work:
CREATE VIEW count_rows AS SELECT COUNT(*) as yy FROM t6;
ALTER TABLE t6 ADD CONSTRAINT max_4_rows check(4<count_rows.yy);

please help...

 

[Xeon SX]

Haven't seen threads with 0 replies for a long time here

anyway if anyone wants to know the solution:

CREATE OR REPLACE RULE max_4_rows AS
ON INSERT TO t6
WHERE 3 < (select count(*) from t6)
DO INSTEAD NOTHING;

 

[jeffy777]

Sorry I didn't reply: I'm a mySQL guy but the syntax is similar.