Question

My database is in SQL Server and I use Linq-to-SQL. I used from SP(Save cards) .
I put breakpoint in my code, when arrive at rdr = cmm.ExecuteReader(); get me exception!!!

 private void btnSave_Click(object sender, EventArgs e)
 {
            PersianCalendar jc = new PersianCalendar();
            string SaveDate = jc.GetYear(DateTime.Now).ToString();
            int from=Convert.ToInt32(txt_barcode_f.Text);
            int to=Convert.ToInt32(txt_barcode_t .Text);
            int quantity=Convert.ToInt32(to-from);
            int card_Type_ID=Convert.ToInt32(cmb_BracodeType .SelectedValue);
            int[] arrCardNum = new int[quantity];

            arrCardNum[0]=from;

             for (int i = from; i < to;i++ )
             {
                 for(int j=0; j<quantity ;j++)
                 {
                 arrCardNum[j]=from+j;
                 int r = arrCardNum[j];
                 sp.SaveCards(r, 2, card_Type_ID, SaveDate, 2);
                 }
             }
        }  

public void SaveCards(int Barcode_Num, int Card_Status_ID, int Card_Type_ID, string Save_Date, int Save_User_ID)
        {

                IDbCommand cmm;
                cmm = Linq.Connection.CreateCommand();
                try
                {           
                    cmm.Parameters.Add(new SqlParameter("@Barcode_Num", Barcode_Num));
                    cmm.Parameters.Add(new SqlParameter("@Card_Status_ID", 2));
                    cmm.Parameters.Add(new SqlParameter("@Card_Type_ID", Card_Type_ID));
                    cmm.Parameters.Add(new SqlParameter("@SaveDate", Save_Date));
                    cmm.Parameters.Add(new SqlParameter("@Save_User_ID", Save_User_ID));
                    cmm.CommandText = "SaveCards";
                    cmm.Connection.Open();
                    cmm.Connection = Linq.Connection;
                    cmm.CommandType = CommandType.StoredProcedure;
                    IDataReader rdr = null;

                    **rdr = cmm.ExecuteReader();**
                    while (rdr.Read())
                    {
                        Console.Write(" All Insert ! " + "\n");
                    }
                }
                catch (SqlException ex)
                {
                    SqlExceptionHandler(ex, Save_User_ID);
                }
                catch (Exception ex)
                {
                    PopularEexceptionHandler(ex, Save_User_ID);
                }
                finally
                { cmm.Connection.Close(); }

        }

when excute sp, show no result and display this:

when execute sp , display this:The INSERT statement conflicted with the CHECK constraint "CK_BarCode_Num". The conflict occurred in database "Parking", table "dbo.TBL_Cards", column 'BarCode_Num'. The statement has been terminated. No rows affected. (0 row(s) returned) @RETURN_VALUE = -6

Answer 1

You’re a bit chaotic on how you set up your connection and command….. e.g. you open the connection before you even assign it! How is that going to work??

My recommendation would be this order (based on the principle first do all the setup before opening the connection, and furthermore open the connection as late as possible, close it as quickly as possible) :

IDbCommand cmm = Linq.Connection.CreateCommand();

try
{           
   // define name and type of command
   cmm.CommandText = "SaveCards";
   cmm.CommandType = CommandType.StoredProcedure;

   // assign connection
   cmm.Connection = Linq.Connection;

   // define parameters
   cmm.Parameters.Add(new SqlParameter("@Barcode_Num", Barcode_Num));
   cmm.Parameters.Add(new SqlParameter("@Card_Status_ID", 2));
   cmm.Parameters.Add(new SqlParameter("@Card_Type_ID", Card_Type_ID));
   cmm.Parameters.Add(new SqlParameter("@SaveDate", Save_Date));
   cmm.Parameters.Add(new SqlParameter("@Save_User_ID", Save_User_ID));

   // only now - after all the setup - open the connection, read the data
   cmm.Connection.Open();

   IDataReader rdr = rdr = cmm.ExecuteReader();

   while (rdr.Read())
   {
      ....
   }
}

To catch the errors that the execution throws, replace your catch block for the SqlException with this:

catch (SqlException ex)
{
   StringBuilder sbErrors = new StringBuilder();

   foreach (SqlError error in ex.Errors)
   {
      sbErrors.AppendLine(error.Message);
   }

   string allErrors = sbErrors.ToString();
}

and debug into that catch block – what is the allErrors string in the end??

Update: after a chat session, we know finally know what the message in the SQL exception is:

The INSERT statement conflicted with the CHECK constraint “CK_BarCode_Num”. The conflict occurred in database “Parking”, table “dbo.TBL_Cards”, column ‘BarCode_Num’.

Now we’re trying to find out what that constraint is / does and why it gets violated….