Hello
I have two Tables.
tblMain(MainID)
tblSec(FamID, Group, MainID)
MainID has same attribute in both tables
tblMain has the correct records.

How can I delete all records from tblSec not present in tblMain? Could you
tell me the kind of query. I'm studying Relational Algebra by myself and this
example would help me to learn
Thanks in advance

Do you want to delete the records from the table or just SHOW the records?

SELECT tblSec.*
FROM tblSec INNER JOIN tblMain
ON tblSec.MainID = tblMain.MainID


DELETE
FROM TblSec
WHERE MainID NOT IN (SELECT MainID FROM tblMain)

John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County

sebastico wrote:
> Hello
> I have two Tables.
> tblMain(MainID)
> tblSec(FamID, Group, MainID)
> MainID has same attribute in both tables
> tblMain has the correct records.
>
> How can I delete all records from tblSec not present in tblMain? Could you
> tell me the kind of query. I'm studying Relational Algebra by myself and this
> example would help me to learn
> Thanks in advance

John And Ken

Many thanks for you help.
John your sql code works and the information by Ken is very useful as well
"John Spencer" wrote:

> Do you want to delete the records from the table or just SHOW the records?
>
> SELECT tblSec.*
> FROM tblSec INNER JOIN tblMain
> ON tblSec.MainID = tblMain.MainID
>
>
> DELETE
> FROM TblSec
> WHERE MainID NOT IN (SELECT MainID FROM tblMain)
>
> John Spencer
> Access MVP 2002-2005, 2007-2010
> The Hilltop Institute
> University of Maryland Baltimore County
>
> sebastico wrote:
> > Hello
> > I have two Tables.
> > tblMain(MainID)
> > tblSec(FamID, Group, MainID)
> > MainID has same attribute in both tables
> > tblMain has the correct records.
> >
> > How can I delete all records from tblSec not present in tblMain? Could you
> > tell me the kind of query. I'm studying Relational Algebra by myself and this
> > example would help me to learn
> > Thanks in advance
> .
>