[SQL] Subquery with IN or EXISTS

Hello, does anybody know why this: SELECT * FROM tab WHERE col1 IN (SELECT col2 FROM TAB2) equals this: SELECT * FROM tab WHERE EXISTS (SELECT col2 FROM TAB2 WHERE col1 = col2) but this: SELECT * FROM tab WHERE col1 IN (SELECT col2 FROM TAB2 WHERE col3='huu') equals _NOT_ this: SELECT * FROM t

Re: [SQL] Subquery with IN or EXISTS

Carl van Tast <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>... > Hi A., > > On 26 Sep 2001 07:24:41 -0700, [EMAIL PROTECTED] (A. Mannisto) > wrote: > > >Hello, > > > >does anybody know why this: > >SELECT * FROM tab WHERE col1 IN (SELECT col2 FROM TAB2) > > > >equals this: > >SE

Re: [SQL] Subquery with IN or EXISTS

Hi A., On 26 Sep 2001 07:24:41 -0700, [EMAIL PROTECTED] (A. Mannisto) wrote: >Hello, > >does anybody know why this: >SELECT * FROM tab WHERE col1 IN (SELECT col2 FROM TAB2) > >equals this: >SELECT * FROM tab WHERE EXISTS (SELECT col2 FROM TAB2 WHERE col1 = >col2) > >but this: >SELECT * FROM tab