I have been staring at this UPDATE statement for a long while and are unsure why my table isn't changing. When I press the button no error appears but my table doesn't not get updated either, I have checked that all of my variables have values on debug and they do.
I'd appreciate any help anyone can give me!
This is the code that contains the statement I need help with:
private void button1_Click(object sender, EventArgs e)
{
string studentanswertext = textBox1.Text;
string connectionString = ConfigurationManager.ConnectionStrings["myconnectionstring"].ConnectionString;
string y = GlobalVariableClass.Signedinteacher;
Convert.ToInt32(y);
MessageBox.Show(y);
MessageBox.Show(Convert.ToString(CurrentQuestionID));
MessageBox.Show(studentanswertext);
SqlConnection connect = new SqlConnection(connectionString);
connect.Open();
SqlCommand command20 = new SqlCommand(@"UPDATE QuestionStudentAssociation SET ([StudentAnswer]=@StudentAnswertext) WHERE ([QuestionID]=@CurrentQID AND [StudentID]=@SignedinStudent )", connect);
command20.Parameters.AddWithValue("@StudentAnswertext", studentanswertext);
command20.Parameters.AddWithValue("@CurrentQID", CurrentQuestionID);
command20.Parameters.AddWithValue("@SignedinStudent", y);
command20.BeginExecuteNonQuery();
connect.Close();
}
This is the whole code for my form if anyone wanted to look at it just in case that is affecting the button even handler:
namespace ComputingA2_Official_Project
{
public partial class CurrentlySetTestForm : Form
{
Timer loopTimer = new Timer();
private int CurrentQuestionID { get; set; }
private string QuestionSpace { get; set; }
public CurrentlySetTestForm()
{
InitializeComponent();
}
private void CurrentlySetTestForm_Load(object sender, EventArgs e)
{
string y = GlobalVariableClass.Signedinteacher;
Convert.ToInt32(y);
string connectionString = ConfigurationManager.ConnectionStrings["myconnectionstring"].ConnectionString;
SqlConnection connect = new SqlConnection(connectionString);
connect.Open();
SqlCommand command18 = new SqlCommand("SELECT MIN([QuestionID]) AS QuestionID FROM QuestionStudentAssociation WHERE ( [StudentID]=@Signedinstudent AND [StudentAnswer] IS NULL )", connect);
command18.Parameters.AddWithValue("@Signedinstudent", y);
var reader = command18.ExecuteReader();
while (reader.Read())
{
CurrentQuestionID = Convert.ToInt32(reader[0]);
SqlCommand command19 = new SqlCommand("SELECT ([Question Space]) FROM Questions WHERE ([QuestionID]=@CurrentQID)", connect);
command19.Parameters.AddWithValue("@CurrentQID", CurrentQuestionID);
using (SqlDataReader reader2 = command19.ExecuteReader())
{
while (reader2.Read())
{
QuestionSpace = Convert.ToString(reader2[0]);
label1.Text = QuestionSpace;
}
}
}
connect.Close();
}
private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
string studentanswertext = textBox1.Text;
string connectionString = ConfigurationManager.ConnectionStrings["myconnectionstring"].ConnectionString;
string y = GlobalVariableClass.Signedinteacher;
Convert.ToInt32(y);
MessageBox.Show(y);
MessageBox.Show(Convert.ToString(CurrentQuestionID));
MessageBox.Show(studentanswertext);
SqlConnection connect = new SqlConnection(connectionString);
connect.Open();
SqlCommand command20 = new SqlCommand(@"UPDATE QuestionStudentAssociation SET ([StudentAnswer]=@StudentAnswertext) WHERE ([QuestionID]=@CurrentQID AND [StudentID]=@SignedinStudent )", connect);
command20.Parameters.AddWithValue("@StudentAnswertext", studentanswertext);
command20.Parameters.AddWithValue("@CurrentQID", CurrentQuestionID);
command20.Parameters.AddWithValue("@SignedinStudent", y);
command20.BeginExecuteNonQuery();
connect.Close();
}
private void timer1_Tick(object sender, EventArgs e)
{
}
}
}
I believe the issue is that you are executing the command asynchronously (BeginExecuteNonQuery), but never calling EndExecuteNonQuery to commit it. I also suspect you could just call it synchronously like this:
command20.ExecuteNonQuery();
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.