Declaring Scalar variable

Question

Hi

I developed an application on Visual C#, connected to the sql management studio. I've been able to get data from the database successfully but have not been able to insert into the database. I'm having an sqlException {"Must declare the scalar variable \"@\"."} and here's my code please what I'm I missing?

        private void button1_Click(object sender, EventArgs e)
        {
            
            string connectionString = @"Data Source=JEREMIAH-HP\SQLEXPRESS;Initial Catalog=CourseInfo;Integrated Security=True";
            SqlConnection sqlCon = new SqlConnection(connectionString);
            SqlCommand command=new SqlCommand("INSERT INTO STUDINFO_TBL(MATRICNO,FIRST_NAME, LAST_NAME, DEPT,LEVEL,CGPA,MODEOFENTRY) VALUES (@MATRICNO, @ FIRST_NAME, @LAST_NAME, @DEPT, @LEVEL, @CGPA, @MODEOFENTRY),sqlCon)");

            command.Parameters.AddWithValue("@MATRICNO", matno.Text);
            command.Parameters.AddWithValue("@FIRST_NAME", frstname.Text);
            command.Parameters.AddWithValue("@LAST_NAME", lastname.Text);
            command.Parameters.AddWithValue("@DEPT", department.Text);
            command.Parameters.AddWithValue("@LEVEL", level.Text);
            command.Parameters.AddWithValue("@CGPA", mycgpa.Text);
            command.Parameters.AddWithValue("@MODEOFENTRY", modeofentry.Text);
            command.Connection = sqlCon;

           sqlCon.Open();
           command.ExecuteNonQuery();
           sqlCon.Close();

           MessageBox.Show("Record Updated!");
           Close();
        }

Answer 1

I guess the issue is with the SqlCommand string; There is a space in FIRST_NAME parameter between '@' and the name. And also you specified the sqlCon object inside the command string. The actual SqlCommand will be as follows:

SqlCommand command=new SqlCommand("INSERT INTO STUDINFO_TBL(MATRICNO,FIRST_NAME, LAST_NAME, DEPT,LEVEL,CGPA,MODEOFENTRY) VALUES (@MATRICNO, @FIRST_NAME, @LAST_NAME, @DEPT, @LEVEL, @CGPA, @MODEOFENTRY)", sqlCon);

Try this.

---

Krishnakumar S

Answer 2

thank you so much I didn't notice it.