[RESOLVED] Opposite of a join

voidstate

I need to delete everything from table A that doesn't have a relationship to table B. I'm sure it can't be too difficult but can't work out how. Basically, I have a table of comments and some are no longer linked to any of the blogs they were submitted to so I want to clean them out.

Table A
comment_id (PK)
blog_id (FK)

Table B
blog_id (PK)

How do I do this?

voidstate

laserlight

This might work:

DELETE FROM "Table A" WHERE blog_id NOT IN(SELECT blog_id FROM "Table B");

EDIT: sorry, you want to delete from "Table A", not "Table B".

voidstate

Thanks - that worked!