[求助]SQL ExecuteReader求助 Post By:2018/3/14 19:33:00 [只看该作者]
老师好:问题如下
Dim cmd As New SQLCommand Dim dt As DataTable cmd.C
cmd.CommandText = "S LECT * From {表A} Where ……" '表A为空,没有一行数据 dt = cmd.ExecuteReader()
If dt Is Nothing Then MessageBox.Show(" ","提示",MessageBoxButtons.OK,MessageBoxIcon.Warning) Return Nothing '没有行记录则直接退出返回 End If dr = dt.DataRows(0) '取记录的第一行 此处报错