笛子曲大漠谱:VB.NET在数据库中修改数据两种方式

来源:百度文库 编辑:偶看新闻 时间:2024/04/27 12:57:35
下面两个程序分别修改数据库computertest.mdb中的表tbtestplaceinfo中的字段“座位余额”的值SeatNo为SeatNo-1。第一种:        Dim CONN As String = "provider=microsoft.jet.oledb.4.0;data source=c:\computertest.mdb"
        Dim sqlconn As New OleDbConnection(CONN)
        Dim SQLString As String
        SeatNo = SeatNo - 1
        SQLString = "update tbtestplaceinfo set 座位余额='" & SeatNo & "'where(考试日期='" & DrDListTestDate.SelectedItem.Text & "') and (考点='" & DrDListTestPlace.SelectedItem.Text & "')"
        Dim cmdtable As OleDbCommand = New OleDbCommand(SQLString, sqlconn)
        cmdtable.CommandType = CommandType.Text
        If sqlconn.State <> ConnectionState.Open Then
            sqlconn.Open()
        End If
        cmdtable.ExecuteNonQuery()
        If sqlconn.State <> ConnectionState.Closed Then
            sqlconn.Close()
        End If第二种:        searchsql = "select * from tbtestplaceinfo where(考试日期='" & DrDListTestDate.SelectedItem.Text & "') and (考点='" & DrDListTestPlace.SelectedItem.Text & "')"
        ADOcmdl = New OleDbDataAdapter(searchsql, "provider=microsoft.jet.oledb.4.0;data source=c:\computertest.mdb")
        ADOcmdl.Fill(ds1, "tbtestplaceinfo")
        mytable1 = ds1.Tables.Item("tbtestplaceinfo")
        Dim myrow As Data.DataRow
        myrow = mytable1.Rows.Item(0)
        myrow.Item("座位余额") = SeatNo - 1
        mytable1.GetChanges()
        cmdl = New OleDbCommandBuilder(ADOcmdl)
        ADOcmdl.Update(ds1, "tbtestplaceinfo")