System.Data.SqlClient.SqlException: "Incorrect syntax near 'studentNo'." how to solve the problem?

Question

SQL

System.Data.SqlClient.SqlException: "Incorrect syntax near 'studentNo'." when i click update button

protected void btnUpdate_Click(object sender, EventArgs e)
        {
            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["StudentConnectionString"].ConnectionString);
            conn.Open();
            string updateQuery = "update Students set firstName = '"+ txtBoxfName + "', lastName = '"+ txtBoxlName +"' studentNo = '" + Convert.ToInt32(txtBoxStudentNo.Text) + "' where id_student = '"+ Convert.ToInt32(txtPK.Text) +"'";
            SqlCommand cmd = new SqlCommand(updateQuery, conn);
            cmd.ExecuteNonQuery();
            Label2.Text = "student successfully updated";

            txtBoxfName.Text = " ";
            txtBoxlName.Text = " ";
            txtBoxStudentNo.Text = " ";

        }

Answer 1

The comma is missing.