.NET (Core and Framework)

Richard Deeming wrote:

I'd suggest posting the DDL of the StudentInfo table.

Richard Deeming wrote:

If the Code column is the primary key, then the statement "i am sure 100% that there is no record that have the same code[^]" doesn't match what the database knows. If that's the case, then my money's on the database being correct!

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

Eddy Vluggen wrote:

Good bet, and more helpfull than a non-related best practice.

Quote:

Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
Dim strconnection As String = "Data Source=ELIANE-VAIO\SQLEXPRESS;Initial Catalog=SchoolDB;Integrated Security=True;"
Dim _cn As SqlConnection = New SqlConnection(strconnection)
_cn.Open()
Dim cmd As New SqlCommand
cmd.CommandText = "INSERT INTO StudentInfo([Code], [Full-Name], [Position], [Title], [Phone-Number], [Address], [Date-Time]) VALUES (@Code, @Name, @Position, @Title, @PhoneNumber, @Address, @DateTime);"
cmd.Parameters.AddWithValue("@Code", Form1.txtCode.Text)
cmd.Parameters.AddWithValue("@Name", Form1.txtName.Text)
cmd.Parameters.AddWithValue("@Position", Form1.cmbPosition.Text)
cmd.Parameters.AddWithValue("@Title", Form1.cmbTitle.Text)
cmd.Parameters.AddWithValue("@PhoneNumber", Form1.txtPhoneNumber.Text)
cmd.Parameters.AddWithValue("@Address", Form1.txtAddress.Text)
cmd.Parameters.AddWithValue("@DateTime", Form1.DateTimePicker1.Value)
Dim cmd1 As New SqlCommand
cmd1.CommandText = "select * from StudentInfo"
MsgBox(cmd1.CommandText.ToString)

_cn.Close()

End Sub

...
cmd.Parameters.AddWithValue("@DateTime", Form1.DateTimePicker1.Value)
cmd.ExecuteNonQuery()

cmd1.CommandText = "select * from StudentInfo where Code = @Code"
cmd1.Parameters.AddWithValue("@Code", Form1.txtCode.Text)

Using con As New SqlConnection(strconnection)
    Using cmd As SqlCommand = con.CreateCommand()
        ...
    End Using
End Using

SAVE BUTTON
-------------

Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
    Try
        Dim strconnection As String = "Data Source=ELIANE-VAIO\SQLEXPRESS;Initial Catalog=SchoolDB;Integrated Security=True;"
        Dim _cn As SqlConnection = New SqlConnection(strconnection)
        Dim cmd As New SqlCommand
        _cn.Open()
        cmd.CommandText = "INSERT INTO StudentInfo([Code], [Full-Name], [Position], [Title], [Phone-Number], [Address], [Date-Time]) VALUES (<a href="/Members/code">@Code</a>, <a href="/Members/Name">@Name</a>, <a href="/Members/position">@Position</a>, <a href="/Members/title">@Title</a>, @PhoneNumber, <a href="/Members/address">@Address</a>, <a href="/Members/datetime">@DateTime</a>);"
        cmd.Connection = _cn
        cmd.Parameters.AddWithValue("<a href="/Members/code">@Code</a>", Val(Me.t1.Text))
        cmd.Parameters.AddWithValue("<a href="/Members/Name">@Name</a>", Me.t2.Text)
        cmd.Parameters.AddWithValue("<a href="/Members/position">@Position</a>", Me.c1.Text)
        cmd.Parameters.AddWithValue("<a href="/Members/title">@Title</a>", Me.c2.Text)
        cmd.Parameters.AddWithValue("@PhoneNumber", Me.t5.Text)
        cmd.Parameters.AddWithValue("<a href="/Members/address">@Address</a>", Me.t6.Text)
        cmd.Parameters.AddWithValue("<a href="/Members/datetime">@DateTime</a>", Me.t7.Value)
        cmd.ExecuteNonQuery()
        _cn.Close()
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub

Private Sub btnRemove_Click(sender As Object, e As EventArgs) Handles btnRemove.Click
        Me.StudentInfoBindingSource.RemoveCurrent()

        Dim con As New SqlConnection
        Dim cmd As New SqlCommand
        Try
            Dim strconnection As String = "Data Source=ELIANE-VAIO\SQLEXPRESS;Initial Catalog=SchoolDB;Integrated Security=True;"
            Dim _cn As SqlConnection = New SqlConnection(strconnection)
            _cn.Open()
            cmd.Connection = _cn
            cmd.CommandText = "Delete From studentInfo where code= " & Val(t1.Text)
            'cmd.Parameters.Add(New SqlParameter("<a href="/Members/code">@code</a>", 99))

            If MessageBox.Show("Do you really want to Delete this Record?", "Delete", MessageBoxButtons.YesNo, MessageBoxIcon.Warning) = DialogResult.No Then
                MsgBox("Operation Cancelled")
                Exit Sub
            Else
                cmd.ExecuteNonQuery()
            End If
        Catch ex As Exception
            MessageBox.Show("Error while deleting record on table..." & ex.Message, "Delete Records")
        Finally
            con.Close()
        End Try
    End Sub

cmd.CommandText = "delete from StudentInfo where Code = @Code"
cmd.Parameters.AddWithValue("@Code", t1.Text)

Member 10388494 wrote:

Here is one of them.

Member 10388494 wrote:

Violation of PRIMARY KEY constraint 'PK_StudentInfo'. Cannot insert duplicate key in object 'dbo.StudentInfo'.

Member 10388494 wrote:

<layer>but i am sure 100% that there is no record that have the same code.

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

enum Gender{
   Male,
   Female
};

dim Male as boolean = RDMale.checked