CODEWITHSUNDEEP
c#sql-server
dyha M
dyha M

Reputation: 25

How to print 2 columns retrieved from SQL Server database

Something missing with the code (I guess). I want to show the student id and name in the list box. But I see this:

enter image description here

I can't figure out the problems especially with the inner join.

private void button1_Click(object sender, EventArgs e)
{
    string strName = "";

    connect.Open();
    SqlCommand command = new SqlCommand(" Select Student_tbl.StudentName, Student_tbl.StudentID, Module_tbl.ModuleID FROM[Course-Student] INNER JOIN Student_tbl ON [Course-Student].SID = Student_tbl.StudentID INNER JOIN Module_tbl ON[Course-Student].CID = Module_tbl.ModuleID WHERE(Module_tbl.ModuleID = '" + tbCourse.Text+"')",connect);

    command.ExecuteNonQuery();

    SqlDataReader reader = command.ExecuteReader();

    while (reader.Read())
    {
       strName = reader[1].ToString();
       listBox1.Items.Add(strName);
    }

    connect.Close();
}

Upvotes: 1

Views: 346

Answers (1)

Gilad Green
Gilad Green

Reputation: 37299

You are printing retrieving from the reader only the StudentID field. Change your while loop as follows to retrieve both fields and concatenate the values:

while (reader.Read())
{
   var name = reader[0].ToString();
   var id = reader[1].ToString();
   listBox1.Items.Add(id + " " + name);
}

You can also use String Interpolation (which is C# 6 syntactic sugar for string.Format) like this:

while (reader.Read())
{
   listBox1.Items.Add($"{reader[1].ToString()} {reader[0].ToString()}");
}

Also, as for the sql statement: Do not use string concatenation to create the statement. This is susceptible for SQL Injections. Use instead Parameterized Queries

Upvotes: 2

Related Questions