I have an desktop application built with vb.net and mysql and it was working good but yesterday I faced problem when I execute a select command:

dim xSql As String = "SELECT
                                p.ID,
                                p.TheName0, 

                                (SELECT IFNULL(SUM(att.S_FinalAmount),0) From tbl_groups_classes_att att 
                                 INNER JOIN tbl_students st 
                                 ON st.ID = att.StudentID
                                 INNER JOIN tbl_groups_classes cls
                                 ON cls.ID = att.ClassID

                                 WHERE st.ParentID = p.ID 
                                and cls.TheDate BETWEEN @Date1 and @Date2 
                                and att.TheStatus <> 'غائب'
                                ) as CurrMost,

                                (SELECT IFNULL(SUM(att.S_FinalAmount),0) From tbl_groups_classes_att att 
                                 INNER JOIN tbl_students st 
                                 ON st.ID = att.StudentID
                                 INNER JOIN tbl_groups_classes cls
                                 ON cls.ID = att.ClassID

                                 WHERE st.ParentID = p.ID and cls.TheDate< @Date1 and att.TheStatus <> 'غائب'
                                ) as PrevMost,

                                (SELECT IFNULL(SUM(pay.TheAmount),0) From tbl_parents_payments pay Where p.ID = pay.ParentID
                                AND pay.TheDate BETWEEN @Date1 and @Date2
                                ) as CurrMadf,

                                (SELECT IFNULL(SUM(pay.TheAmount),0) From tbl_parents_payments pay Where p.ID = pay.ParentID
                                AND pay.TheDate < @Date1
                                ) as PrevMadf,

                                (SELECT CurrMost   PrevMost) as AllMost,
                                (SELECT CurrMadf   PrevMadf) as AllMadf,
                                (SELECT AllMost - AllMadf) AS FinalTotal 

                                from tbl_parents p"


  xDS = New Ds_Edsa
            Dim xCMD4 As New MySqlCommand(xSql, Conn)
            xCMD4.Parameters.Add("@Date1", MySqlDbType.Date).Value = CDate(xxFrom)
            xCMD4.Parameters.Add("@Date2", MySqlDbType.Date).Value = CDate(xxTo)
            xDadp = New MySqlDataAdapter(xCMD4)
            xDadp.Fill(xDS.Tables("AllPar"))

the problem only in the online mysql hosting but when I run the command on localhost (mysql) it's working!

before everything was good so it's a new problem

the error that I get is (fatal error encountered during command execution)

CodePudding user response：

I think that your SQL is very complicated, so you should know the count of the records that you are processing and I think you should separate the commands to get each part in one command and then merge them in one data table inside the dataset.