Question

Using PHP, for-each row in a MySQL query’s result set, I need to execute another MySQL query. So far, I’ve got

$result = mysql_query("SELECT id, state FROM states WHERE region='given_region'")
or die(mysql_error());

while($row = mysql_fetch_row($result))
{
    $state = $row['state'];
    $r = mysql_query("SELECT * FROM locations WHERE state REGEXP '(^|,)".$state."($|,)'");
}

Now I need to append all of the results $r into ONE result set that I can then iterate through with a standard while-loop, however, my very limited PHP skills are leaving me at a loss getting code to do that.

Can anyone provide any insight into how I’d go about appending all the results into one set within the given while loop?

Thanks!

Answer 1

Learn about SQL joins:

SELECT states.id, states.state, locations.*
FROM   states LEFT JOIN locations USING(state)
WHERE  states.region = 'given_region'