Re: SQL for DELETE using subquery?

Douglas Wilson wrote: > On Thu, 25 Jun 1998 15:21:02 -0700, Roger Tomas <tomasr@agcs.com> > wrote: > > >Informixites... > > > >I'm trying to delete rows from one table that are not referenced > >by any rows in a second table. The referencing key consists of > >2 columns. It seems you can't use table aliases in delete > >statements to do the type of subquery I expected to use. I've > >found a way to do this (below) but it seems like a hack. Any > >better way? Schema changes are not an option. Engine is 7.23. > > <snip> > OR: > > delete from tableb > where not exists > (select 1 from tablea a > where a.col1=tableb.col1 > and a.col2=tableb.col2) Does this do the correlation correctly? Roger Tomas AG Communication Systems