dboperation.vb

用VB开发了一个超市管理系统

Public Class DBOperation
    Shared Function DBOperate(ByVal SQLString As String) As DataTable
        ' Try
        Dim oleconn As New OleDb.OleDbConnection(CONN)
        Dim cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand(SQLString, oleconn)
        cmd.CommandType = CommandType.Text
        Dim sTokens() As String
        sTokens = SQLString.Split(" ")
        If Strings.InStr("INSERT,DELETE,UPDATE", sTokens(0).ToUpper) Then
            If oleconn.State <> ConnectionState.Open Then
                oleconn.Open()  '打开数据库连接
            End If
            cmd.ExecuteNonQuery()  '执行SQL语句
            If oleconn.State <> ConnectionState.Closed Then
                oleconn.Close() '关闭数据库连接
            End If
            If sTokens(0).ToUpper = "INSERT" Then
                MsgBox("插入记录成功")
            End If
            If sTokens(0).ToUpper = "DELETE" Then
                MsgBox("删除记录成功")
            End If
            If sTokens(0).ToUpper = "UPDATE" Then
                MsgBox("更新记录成功")
            End If
            Return Nothing
        Else
            Dim ObjectdsDataSet As New DataSet()
            Dim adapter As New OleDb.OleDbDataAdapter()
            adapter.TableMappings.Add("Table", "TEMP")
            adapter.SelectCommand = cmd
            If oleconn.State <> ConnectionState.Open Then
                oleconn.Open()  '打开数据库连接
            End If


            cmd.ExecuteNonQuery()  '执行SQL语句
            If oleconn.State <> ConnectionState.Closed Then
                oleconn.Close() '关闭数据库连接
            End If
            adapter.Fill(ObjectdsDataSet) '填充数据集
            Return ObjectdsDataSet.Tables("TEMP")
        End If
        ' Catch
        ' MsgBox(Err.Description)
        '  End Try
    End Function

End Class