Vb.Net程序设计：一个好用的数据库操作类的模板

Imports System.Data
Imports System.Data.SqlClient
Public Class UserClass
Dim sql As String
Public Function Add(ByVal dm As Object) As Boolean
Dim pr(10) As SqlParameter
sql = "insert into tbl() values "
sql = sql & "()"
If SQLHelperExt.ExecuteNonQuery(sql, pr) >= 1 Then
Return True
Else
Return False
End If
End Function
Public Function Update(ByVal dm As Object) As Boolean
Dim pr(10) As SqlParameter
sql = "update tbl set x=@x where id=" & dm
If SQLHelperExt.ExecuteNonQuery(sql, pr) >= 1 Then
Return True
Else
Return False
End If
End Function
Public Function Delete(ByVal id As String) As Boolean
sql = "delete from tbl where id=" & id
sql = "update tbl set strStatus='void' where id=" & id
SQLHelperExt.ExecuteNonQuery(sql)
End Function
Public Function CheckRsExist(ByVal id As String) As Boolean
sql = "select 1 from tbl where id=" & id
Return SQLHelperExt.CheckRsExist(sql)
End Function
Public Function GetTable() As DataTable
Return Me.GetTable("")
End Function
Public Function GetTable(ByVal id As String) As DataTable
Return Nothing
End Function
Public Function GetTableCN() As DataTable
Return Me.GetTableCN("")
End Function
Public Function GetTableCN(ByVal id As String) As DataTable
Return Nothing
End Function
End Class