Hi, I need help on following code I have to run two queries to update records on two different tables, need to help how to run $q4 query like $q3 query. if(mysql_query($query)) { echo '<div><div class="alert alert-success"><strong>Product added sucessfully.</strong></div></div>'; $item_added=true; $product_name=$_POST['product_name']; //providing particular's name to variable $article $product_name; $q2="SELECT SUM(`quantity_in`) FROM `av_products_in` WHERE `product_name`='$product_name' Group By `product_name`"; $q2_run=mysql_query($q2); $q2_total=mysql_result($q2_run,0); $q2_total; $q1="SELECT SUM(`quantity`) FROM `av_orders` WHERE `product_name`='$product_name' Group By `product_name`"; $q1_run=mysql_query($q1); $q1_total=mysql_result($q1_run,0); $q1_total; $total=$q2_total-$q1_total; $total; $qr="SELECT piece_per_box FROM av_products WHERE `product_name`='$product_name'"; $piece_per_box=mysql_result(mysql_query($qr),0); $box=$total/$piece_per_box; $q3="UPDATE av_products_in SET balance=$total,boxes=$box WHERE product_name='$product_name'"; // echo $q4="UPDATE av_products SET boxes=$box WHERE product_name='$product_name'"; // 2 lines can be commented- if(mysql_query($q3)) echo "Quantity updated"; } else echo '<div class="alert alert-success"><strong>Problem in adding Product.</strong></div>'; Thanks
You can't update fields from multiple tables on a single update query. There error you are getting is because this is not permitted: Since you can only update one table per update command. However you can join them if you only changing value from one table only