Question

How can I make:

DELETE FROM foo WHERE id=1 AND bar not contains id==1

To elaborate, how can I remove a row with id = 1, from table foo, only if there is not a row in table bar with id = 1.

Answer 1

DELETE FROM foo WHERE id=1 AND NOT EXISTS (SELECT * FROM bar WHERE id=1) 

I’m assuming you mean that foo and bar are tables, and you want to remove a record from foo if it doesn’t exist in bar.