From the documentation
mysql> SELECT table1.* FROM table1
-> LEFT JOIN table2 ON table1.id=table2.id
-> WHERE table2.id IS NULL;
will normally give you the right answer.
and you should get : 2026 x 240 - 486,057 = 183 results
Aaron Wolski wrote:
> Hi all,
>
> Having a problem with a query that's returning 486,057 results when it
> most definitely should NOT be doing that.
>
> I have two tables:
>
> 1 for a list of customers that purchase product A, another for customers
> who purchased product B.
>
> Columns are:
>
> Id
> First
> Last
> Email
>
> I am trying to compare table 1 to table 2 to get a result set that gives
> me the contact info (table columns) for those whose email addresses in
> table 1 DON'T EQUAL those in table two.
>
> In table one I have 2026 records
> In table two I have 240 records
>
> The query is this:
>
> SELECT * FROM producta_customers AS t1, productb_customers AS t2 WHERE
> t1.email != t2.email
>
> When I do this query. I get 486,057 results returne.
>
> Where am I going wrong? Any ideas?
>
> Thanks so much for the help!
>
> Aaron
>
>
>
--
Philippe Poelvoorde
COS Trading Ltd.
+44.(0)20.7376.2401
philippe@stripped