Dim info As String '返回的字符串
'数据库连接字符
Dim connstr As String = ""
'数据库查询语句
Dim sel As String = ""
'数据库连接类
Dim oleconn As New System.Data.OleDb.OleDbConnection(connstr)
'数据库命令类
Dim olecomm As New System.Data.OleDb.OleDbCommand
'初始化命令类
olecomm.CommandText = sel
olecomm.Connection = oleconn
'读数据库类
Dim read As System.Data.OleDb.OleDbDataReader
oleconn.Open()
read = olecomm.ExecuteReader()
'如果存在用户执行
If (read.Read()) Then