SELECT COUNT( tblproduct.Product_ID ) AS num_Product, tblproduct.Group_ID, tblproduct.Product_ID, tblproduct.ProductName
FROM tblproduct, tblproductsale
WHERE tblproduct.Product_ID = tblproductsale.Product_ID
AND tblproductsale.Allow =1
AND tblproductsale.BeginDate <= '$cBeginDate'
AND tblproductsale.EndDate >= '$cEndDate'
GROUP BY tblproduct.Product_ID
ORDER BY ProductName
ผลที่ได้คือ:Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '='
Load balance : Server 01
