用户注册时,如何判断用户重名?先谢谢了~~~
代码如下:
<%@ Import Namespace="System.Data" %>
<%@ Import NameSpace="System.Data.OleDb" %>
<%@ page Language="VB" Debug="true"%>
<script runat="server">
Dim myConnection As OleDbConnection
Dim myCommand As OleDbCommand
Dim null AS DBnull
dim username as string,password as string
sub page_load(obj as object,e as eventargs)
username = request.QueryString("username")
password = request.QueryString("password")
if(username = "" or password = "")
response.write("用户名和密码不能为空")
end if
if(username <> "" and password <>"")
dim dbname as string
dbname=server.mappath("admin/dbnews.mdb")
myConnection = New OleDbConnection( "PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA Source="&dbname )
myConnection.Open()
myCommand = New OleDbCommand( "select * FROM dbuser where dbusername="&username, myConnection )
response.write(myCommand)
'这里应该怎么判断啊?数据库是acess的
'下面是插入到数据库的东西
myCommand = New OleDbCommand( "Insert INTO dbuser(dbusername,dbpassword) Values('"& username &"','"& password &"')", myConnection )
myCommand.ExecuteNonQuery()
response.write("注册成功")
response.write(myCommand)
MyConnection.Close()
end if
end sub
</script>
如何判断用户名重名?