Check and update the row depending on same or different value

Question

I am trying to update the status if all the rows value is set to same value.

my query like this

$ord = "SELECT * FROM plitems WHERE pur_order_id='".$order_id."'";
    $ord1 = mysqli_query($con, $ord);

    while($ord2 = mysqli_fetch_array($ord1)) {

        if(($ord2['invoice_status']=='Invoiced')) 
        {
            $m5 = mysqli_query($con, "UPDATE pur_orders SET status='Invoiced' WHERE pur_order_id='".$order_id."'");

        }
        else
        {
            $m5 = mysqli_query($con, "UPDATE pur_orders SET status='Partial' WHERE pur_order_id='".$order_id."'");

        }

But here i have 2 line items in plitems table, 1st line item status is Invoiced and 2nd line item status is Partial , But still it is setting pur_orders status as Invoiced instead of Partial

Answer 1

Use a query that uses GROUP BY to find the orders that have all the same status.

UPDATE pur_orders AS p
CROSS JOIN (
      SELECT MAX(invoice_status) AS invoice_status
      FROM plitems
      WHERE pur_order_id = $order_id
      HAVING COUNT(DISTINCT invoice_status) = 1) AS t
SET p.status = t.invoice_status
WHERE p.pur_order_id = $order_id

If there's just one status, the subquery will return one row with that status, and it will then be assigned to pur_orders.status . If there's more than one status, the subquery will return no rows, so the CROSS JOIN will produce an empty cross product, and it won't update anything.

DEMO