Why can't I delete it. . DataGrid CheckBox selection delete problem

jin1120

Dim i As Integer
        Dim ChBox As CheckBox
        For i = 0 To DataGrid1.Items.Count-1
            ChBox = CType (DataGrid1.Items (i) .Cells (0) .FindControl ("CheckBox1"), CheckBox)
            If ChBox.Checked = True Then
                Dim conn As New SqlConnection
                conn.ConnectionString = "server = 127.0.0.1; uid = sa; pwd =; database = netexam"
                conn.Open ()
                Dim sql As String
                sql = "delete from question where id = ChBox"
                Dim cmd As New SqlCommand (sql, conn)
                cmd.ExecuteNonQuery ()
                bind ()
            End If
        Next

saintfrosty

Remove bind ().

If there are still problems, you should debug, and then follow the debugging to give a more clear description of how you judged that you can't delete it.

xinyu5460

sql = "delete from question where id = ChBox"
There is a problem with this statement. You did not assign the ID correctly. There is no id = ChBox data in the database. You should define a hidden template column and define a Label to help determine the id field.
<asp: TemplateColumn>
<ItemTemplate>
<asp: Label runat = "server" Text = '<% # DataBinder.Eval (Container, "DataItem.id")%>'>
</ asp: Label>
</ ItemTemplate>
</ asp: TemplateColumn>

then

 Dim i As Integer
 Dim ChBox As CheckBox
 Dim label1 As Label

For i = 0 To DataGrid1.Items.Count-1
            ChBox = CType (DataGrid1.Items (i) .Cells (0) .FindControl ("CheckBox1"), CheckBox)

label1 = CType (DataGrid1.Items (1) .FindControl ("label1"), Label)
If ChBox.Checked = True Then
                Dim conn As New SqlConnection
                conn.ConnectionString = "server = 127.0.0.1; uid = sa; pwd =; database = netexam"
                conn.Open ()
                Dim sql As String
                sql = "delete from question where id = '" + label1.Text + "'";
                Dim cmd As New SqlCommand (sql, conn)
                cmd.ExecuteNonQuery ()
                bind ()
            End If
        Next

xinyu5460

The definition of the template column should be as follows, almost wrong
<asp: TemplateColumn>
<ItemTemplate>
<asp: Label runat = "server" ID = "label1" Text = '<% # DataBinder.Eval (Container, "DataItem.id")%>'>
</ asp: Label>
</ ItemTemplate>
</ asp: TemplateColumn>

jin1120

Thanksxinyu5460for the answer. . But there are still errors! I posted the code to help me see what went wrong? My thought is to use the DataGrid to do the test paper review function of the test system. . Use the outer CheckBox to select the CheckBox inside the DataGrid. . Then use the button to submit or delete the selected questions.
-------------------------------------------------- ----------------
<Columns>
<asp: TemplateColumn>
<ItemTemplate>
<asp: CheckBox id = "CheckBox1" runat = "server" AutoPostBack = "True"> </ asp: CheckBox>
</ ItemTemplate>
</ asp: TemplateColumn>
<asp: TemplateColumn>
<ItemTemplate>
<asp: Label runat = "server" ID = "Label1" Text = '<% # DataBinder.Eval (Container, "DataItem.id")%>'>
</ asp: Label>
</ ItemTemplate>
</ asp: TemplateColumn>
<asp: BoundColumn DataField = "question" HeaderText = "Question </ </ :: BoundColumn>
<asp: BoundColumn DataField = "A" HeaderText = "Option A"> </ asp: BoundColumn>
<asp: BoundColumn DataField = "B" HeaderText = "Option B"> </ asp: BoundColumn>
<asp: BoundColumn DataField = "C" HeaderText = "OptionC"> </ asp: BoundColumn>
<asp: BoundColumn DataField = "D" HeaderText = "Option D"> </ asp: BoundColumn>
<asp: BoundColumn DataField = "answer" HeaderText = "answer"> </ asp: BoundColumn>
<asp: BoundColumn DataField = "type" HeaderText = "Exam Question Type"> </ asp: BoundColumn>
<asp: BoundColumn DataField = "subjectname" HeaderText = "Examination Subjects"> </ asp: BoundColumn>
</ Columns>
-------------------------------------------------- ---------------------
        Dim i As Integer
        Dim ChBox As CheckBox
        Dim label1 As Label

        For i = 0 To DataGrid1.Items.Count-1
            ChBox = CType (DataGrid1.Items (i) .Cells (0) .FindControl ("CheckBox1"), CheckBox)

            label1 = CType (DataGrid1.Items (1) .FindControl ("label1"), Label)
            If ChBox.Checked = True Then
                Dim conn As New SqlConnection
                conn.ConnectionString = "server = 127.0.0.1; uid = sa; pwd =; database = netexam"
                conn.Open ()
                Dim sql As String
                sql = "delete from question where id = '" + label1.Text + "'"
                Dim cmd As New SqlCommand (sql, conn)
                cmd.ExecuteNonQuery ()
                bind ()
            End If
        Next

xinyu5460

Because you did not call the Bind () method at the end of the loop, if you select something other than the first line, the following CheckBox selections are all ineffective. You only need to put the Bind () call after the For loop and it is OK , as follows.
Dim i As Integer
        Dim ChBox As CheckBox
        Dim label1 As Label

        For i = 0 To DataGrid1.Items.Count-1
            ChBox = CType (DataGrid1.Items (i) .Cells (0) .FindControl ("CheckBox1"), CheckBox)

            label1 = CType (DataGrid1.Items (1) .FindControl ("label1"), Label)
            If ChBox.Checked = True Then
                Dim conn As New SqlConnection
                conn.ConnectionString = "server = 127.0.0.1; uid = sa; pwd =; database = netexam"
                conn.Open ()
                Dim sql As String
                sql = "delete from question where id = '" + label1.Text + "'"
                Dim cmd As New SqlCommand (sql, conn)
                cmd.ExecuteNonQuery ()
            End If
        Next
  bind ()

liukai9911

sql = "delete from question where id = ChBox"
There is a problem with this statement

liukai9911

Better learn to debug by yourself

jin1120

There is another problem. . How to submit the selected topic of the CheckBox in the DataGrid to another table in the database?

xinyu5460

I don't quite understand what your problem is! You have to use the selected data to generate data in another table. Use the Insert statement.