vb.net 如何检查 DataReader 是否有数据？
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时间：2020-09-09 14:32:24 来源:igfitidea点击:
How Can I check whether DataReader has Data or not?
提问by RedsDevils
Again I have problem with checking whether DataReader object has data or not?
我再次在检查 DataReader 对象是否有数据时遇到问题？
Dim cmd as SqlCommand
Dim drd as SqlDataReader
cmd = New SqlCommand ("SELECT * FROM Stock", conx)
drd = cmd.ExecuteReader()
''HERE I WOULD LIKE TO CHECK WHETHER drd has Data or not
While (drd.Read())
{
txtName.Text = drd.Item("StockName")
}
How can I check that? Please Help me! Thanks all in advcance!
我该如何检查？请帮我！先谢谢大家！
回答by richeym
if(drd.HasRows)
{
//....
}
回答by Sensa
Yes you can with drd.read()
是的，您可以使用 drd.read()
Like:
喜欢：
If drd.read() Then
...do things with data...
Else
...show message box... or just skip.
End If
回答by ZippyV
drd.Read() will return False when there is no data. You don't have to change your code.
drd.Read() 将在没有数据时返回 False。您不必更改代码。
