I'm not 100% certain about this, but I believe you want to look at using a
LEFT OUTER JOIN
At 11:37 AM 4/4/01 -0400, bill wrote:
>If I want to find a list of items in one table whose id does not appear
>in another table, can that be done in one query?
>
>I can only figure it out if I use two queries.
>
>$result=mysql_query("SELECT id,item FROM table1");
>
>while ($row=mysql_fetch_array($result)) {
> $thisid=$row["id"];
> $thisitem=$row["item"];
> $ckresult=mysql_query("SELECT id FROM table2 WHERE id=$thisid");
> if (!mysql_num_rows($ckresult)) {
> echo "$thisitem using id $thisid is in table 1 but does not
>appear in table 2<BR>";
> } // end if
>
>} // end while
>
>
>
>kind regards,
>
>bill hollett
>
>
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