select sum mysql code example

Example 1: using sum function in mysql for two diffrenet conditions

SELECT 
    SUM(CASE
        WHEN status = 'Shipped' THEN quantityOrdered
    END) qty_shipped,
    SUM(CASE
        WHEN status = 'Resolved' THEN quantityOrdered
    END) qty_resolved,
    SUM(CASE
        WHEN status = 'Cancelled' THEN quantityOrdered
    END) qty_cancelled,
    SUM(CASE
        WHEN status = 'On Hold' THEN quantityOrdered
    END) qty_on_hold,
    SUM(CASE
        WHEN status = 'Disputed' THEN quantityOrdered
    END) qty_on_disputed,
    SUM(CASE
        WHEN status = 'In Process' THEN quantityOrdered
    END) qty_in_process
FROM
    orderdetails
        INNER JOIN
    orders USING (orderNumber);

Example 2: sum mysql column

SELECT sum( mark ) FROM `student`

Example 3: mysql select inside sum

SELECT x.prod_name
     , SUM(x.total)
  FROM ( SELECT bp.prod_name
              , ( SELECT SUM( wh.quantity ) * bp.weight 
                    FROM bus_warehouse_entries wh
                   WHERE bp.prod_code = wh.org_product_code ) AS total
       FROM bus_products bp ) x
 GROUP BY x.prod_name