VB.NET与SQL Server的连接

Question

I had a project running perfectly ie entering values in database linked by code. But in the other project I am implementing it shows values correctly submitted, gives no error while running but values are not entered in database.

Private Sub frmAddresume_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    cn.ConnectionString = "Data Source=ROHAN-PC\SQLEXPRESS;initial catalog=Libeasy;Integrated Security=true"

    DateTimePicker1.Value = DateTime.Now.ToShortDateString()
End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
    If (TextBox1.Text <> "" And TextBox2.Text <> "" And TextBox3.Text <> "") Then
        cn.Open()
        cmd.Connection = cn
        cmd.CommandText = "insert into StudResume values('" + TextBox1.Text + "','" + TextBox2.Text + "','" + DateTimePicker1.Value.ToShortDateString() + "'," + TextBox3.Text + ")"

        cmd.Dispose()
        cn.Close()

        MsgBox("Details saved Successfully", MsgBoxStyle.Information, "Done")
        TextBox1.Text = ""
        TextBox2.Text = ""
        TextBox3.Text = ""

        DateTimePicker1.Value = Now
        TextBox1.Focus()
    Else
        MsgBox("Please Enter Complete Details", MsgBoxStyle.Critical, "Error")
    End If
End Sub

Answer 1

You've missed the executenonquery() ,so the query you have provided is niether executed.replace the below code and eeverything will be working.

cmd.Connection = cn
        cmd.CommandText = "insert into StudResume values('" + TextBox1.Text + "','" + TextBox2.Text + "','" + DateTimePicker1.Value.ToShortDateString() + "'," + TextBox3.Text + ")"
cmd.ExecuteNonQuery()
        cmd.Dispose()
        cn.Close()

Ie Add cmd.ExecuteNonQuery() after providing the commandtext.

Answer 2

change your button3 code as the following, it will give u an error message in msgbox, post the error message here so may we can help,

        If (TextBox1.Text <> "" And TextBox2.Text <> "" And TextBox3.Text <> "") Then
            Try
                cn.Open()
                cmd.Connection = cn
                cmd.CommandText = "insert into StudResume values('" + TextBox1.Text + "','" + TextBox2.Text + "','" + DateTimePicker1.Value.ToShortDateString() + "'," + TextBox3.Text + ")"

                cmd.Dispose()
                cn.Close()

                MsgBox("Details saved Successfully", MsgBoxStyle.Information, "Done")
                TextBox1.Text = ""
                TextBox2.Text = ""
                TextBox3.Text = ""

                DateTimePicker1.Value = Now
                TextBox1.Focus()
            Catch ex As Exception
                MsgBox(ex.Message)
            Finally

            End Try

        Else
            MsgBox("Please Enter Complete Details", MsgBoxStyle.Critical, "Error")
        End If

Answer 3

尝试这种方式cn = new SqlConnection（“数据源= ROHAN-PC \\ SQLEXPRESS;初始目录= Libeasy；集成安全性= true”）