结果没有出现在列表框中

Question

May I know what's wrong with my code below.. 'cause it doesn't show the result. I want to view the name of employees, their number of activities per month, then their average grade by dividing the num. of activities to their score. I hope you can help me to do this. I want to view it on list box

the format is this:

Juan Dela Cruz
Count: 10    
Score: 5
Grade: 2

econ = new SqlConnection();
econ.ConnectionString = emp_con;
econ.Open();
int found = -1;
string Log_User, Count, Score;
int iGrade = 0;
string n = "";
string strScore = "Score: ";
string strGrade = "Grade: ";
string strCount = "Count: ";
ecmd = new SqlCommand("SELECT Log_User, Count = COUNT(Det_Score), Score = SUM(Det_Score) FROM MEMBER M,DETAILS D WHERE D.Emp_Id = M.Emp_Id AND Month(Sched_Start) like" + "'" + comMonth.Text + "'AND Year(Sched_Start) like" + "'" + txtYear.Text + "'GROUP BY Log_User", econ);
ecmd.CommandType = CommandType.Text;
ecmd.Connection = econ;
dr = ecmd.ExecuteReader();
listBox1.Text = txtYear.Text;
listBox1.Text = comMonth.Text;
while (dr.Read())
{
 Log_User = (string)dr["Log_User"];
 Count = (string)dr["Count"];
 Score = (string)dr["Score"];
 iGrade = Convert.ToInt32(Count) / Convert.ToInt32(Score);
 found += 1;
 listBox1.Items.Insert(found, Convert.ToString(n));
 listBox1.Items.Insert(found, Convert.ToString(strGrade) + Convert.ToString(iGrade));
 listBox1.Items.Insert(found, Convert.ToString(strScore) + Convert.ToString(Score));
 listBox1.Items.Insert(found, Convert.ToString(strCount) + Convert.ToString(Count));
 listBox1.Items.Insert(found, Convert.ToString(Log_User));
 listBox1.Items.Insert(found, Convert.ToString(n));
}

econ.Close();
}
catch (Exception x)
{
  MessageBox.Show(x.GetBaseException().ToString(), "Connection Status", MessageBoxButtons.OK, MessageBoxIcon.Error);
}

I want to view the result here but I can't see the output. Is there any problem in my sql statement?? In MS SQL 2005 when I run the sql, it run smoothly but when I run it to VS 2010, it doesn't appear.

Answer 1

Can be a couple of problem.

Did u try running the sql statement in Sql Management Studio?

Did they have any results?

If so, try use

listbox1.Items.Add instead of Insert

No exception error, rite?

If I were you, I'd use sqlDataAdapter and put all results into datatable then I would check whether the datatable has any rows. If so, I will loop and add them into listbox.

Answer 2

I changed your code in a way it should work:

econ = new SqlConnection(); 
econ.ConnectionString = emp_con; 
econ.Open(); 
string Log_User, Count, Score; 
int iGrade = 0; 
string n = ""; 
string strScore = "Score: "; 
string strGrade = "Grade: "; 
string strCount = "Count: "; 
ecmd = new SqlCommand("SELECT Log_User, Count = COUNT(Det_Score), Score = SUM(Det_Score) FROM MEMBER M,DETAILS D WHERE D.Emp_Id = M.Emp_Id AND Month(Sched_Start) like" + "'" + comMonth.Text + "'AND Year(Sched_Start) like" + "'" + txtYear.Text + "'GROUP BY Log_User", econ); 
ecmd.CommandType = CommandType.Text; 
ecmd.Connection = econ; 
dr = ecmd.ExecuteReader(); 
listBox1.Items.Add(txtYear.Text); 
listBox1.Items.Add(comMonth.Text); 
while (dr.Read()) 
{ 
 Log_User = (string)dr["Log_User"]; 
 Count = (string)dr["Count"]; 
 Score = (string)dr["Score"]; 
 iGrade = Convert.ToInt32(Count) / Convert.ToInt32(Score); 
 listBox1.Items.Add(string.Format("{0}", n)); 
 listBox1.Items.Add(string.Format("Grade: {0}", iGrade))); 
 listBox1.Items.Add(string.Format("Score: {0}",  Score))); 
 listBox1.Items.Add(string.Format("Count: {0}", Count)); 
 listBox1.Items.Add(Log_User); 
 listBox1.Items.Add(n.ToString()); 
} 

econ.Close(); 
} 
catch (Exception x) 
{ 
  MessageBox.Show(x.GetBaseException().ToString(), "Connection Status", MessageBoxButtons.OK,     MessageBoxIcon.Error); 
} 

Answer 3

Your biggest issue is going to be your SQL statement, specifically the likes. You don't add the %, so unless that is typed in by the user, you won't get any results.

Also, I don't think that like is appropriate in that context since you are looking for a month number.

Finally, you should use parameters to prevent SQL injection, but I'll leave that as another exercise.

Here is the minimum change you need:

ecmd = new SqlCommand("SELECT Log_User, Count = COUNT(Det_Score), Score = SUM(Det_Score) FROM MEMBER M,DETAILS D WHERE D.Emp_Id = M.Emp_Id AND Month(Sched_Start) = " + comMonth.Text + " AND Year(Sched_Start) = " + txtYear.Text + " GROUP BY Log_User", econ);

Also, you don't need to use insert on the list items, you should use add instead:

listBox1.Items.Add(Convert.ToString(n));
etc...

And finally, you should cast the values from the database in case they contain DBNulls:

Log_User = dr["Log_User"] as string;
etc...

Answer 4

Replace Insert to Add.

 if (dr == null || !dr.HasRows) {
                                 //No records found
                                }
     else
       {
     listBox1.Items.Add(found, Convert.ToString(n));
     listBox1.Items.Add(found, Convert.ToString(strGrade) + Convert.ToString(iGrade));
     listBox1.Items.Add(found, Convert.ToString(strScore) + Convert.ToString(Score));
     listBox1.Items.Add(found, Convert.ToString(strCount) + Convert.ToString(Count));
     listBox1.Items.Add(found, Convert.ToString(Log_User));
     listBox1.Items.Add(found, Convert.ToString(n));
      }

Regards

Answer 5

Are you absolutely sure that SQL query runs correctly in SQL Mgmt studio? You're not grouping on the Count field (at the very least), so you should get an aggregate error.

Also, you might want to a proper join, and not join via a WHERE clause (personal preference).

Actually, your SQL Statement seems broken. Try this:

SELECT Log_User, COUNT(Det_Score) as count, SUM(Det_Score) as Score
FROM MEMBER M
    JOIN DETAILS D on M.Emp_Id = D.Emp_Id
WHERE MONTH(Sched_Start) like + "' + comMonth.Text + '" AND YEAR(Sched_Start) LIKE "' + txtYear.Text '"
GROUP BY Log_User, COUNT(Det_Score) as count, SUM(Det_Score) as Score

Answer 6

listBox1.Items.Clear();
listBox1.Text = "";
econ = new SqlConnection();
econ.ConnectionString = emp_con;
econ.Open();
float iGrade = 0;
float Grade = 0.00F;
string Log_User;
float Count, Score;
string n = "";
string strScore = "Score: ";
string strGrade = "Grade: ";
string strCount = "Count: ";
string date = DateTime.Now.ToShortTimeString();
ecmd = new SqlCommand("SELECT Log_User, Count = COUNT(Det_Score), Score = SUM(Det_Score) FROM MEMBER M,DETAILS D WHERE D.Emp_Id = M.Emp_Id AND Log_User like" + "'" + Convert.ToString(comEmployee.Text) + "'AND Month(Sched_Start) =" + "'" + Convert.ToInt32(iMonth) + "'AND Year(Sched_Start) =" + "'" + Convert.ToInt32(txtYear.Text) + "'GROUP BY Log_User", econ);
ecmd.CommandType = CommandType.Text;
ecmd.Connection = econ;
dr = ecmd.ExecuteReader();
listBox1.Items.Add("As of " + date + ": "+ comMonth.Text + ", "+ txtYear.Text);
while (dr.Read())
{
   if (dr == null || !dr.HasRows)
   {
      MessageBox.Show("No record found.", "Error");
   }
   else
   {
      Log_User = (string)dr["Log_User"];
      Count = (dr["Count"] as int?) ?? 0;
      Score = (dr["Score"] as int?) ?? 0;
      try
      {
         iGrade = Score / Count;
         Grade = iGrade * 100;
      }
      catch (DivideByZeroException)
      {
          Console.WriteLine("Exception occured");
      }
      listBox1.Items.Add(Convert.ToString(n));
      listBox1.Items.Add(Convert.ToString(Log_User));
      listBox1.Items.Add(Convert.ToString(strCount + Count));
      listBox1.Items.Add(Convert.ToString(strScore + Score));
      listBox1.Items.Add(Convert.ToString(strGrade + Grade));
      }
   }               
   econ.Close();

the code above is my answer for my question..I hope it can help others. Thanks to those people who helped me to figured it out.. :D God bless