主题：如何后台全局禁止重复数据 急急急

If e.DataCol.Name = "客户名称" Then

    Dim cmd As New SQLCommand

    cmd.CommandText = "select count(客户名称) from {客户信息表} where 客户名称='" & e.newValue & "'"

    Dim result As Integer = cmd.ExecuteScalar

    If result > 0 Then

        MessageBox.Show("此客户已经存在!")

        e.Cancel = True

    End If

End If