vb连接数据库怎么直接重新连接数据库

vb连接数据库怎么直接重新连接数据库

1，你是什么数据库看比如：ACCESS,SQL
2，可以现在ACCESS或SQL环境里建立数据库，当然也可以VB里建立。

系统登录窗口，vb连接sqlserver private sub cmdok_click() dim sql as string dim rs_login as new adodb.recordset dim conn as new adodb.connection conn.open "provider=microsoft.jet.oledb.4.0; data source=" & app.path & "\database.mdb" if trim(text1.text) = "" then msgbox "用户名不能为空，请重新输入！" text1.setfocus else sql = "select * from 用户表 where user_id='" & trim(text1.text) & "'" rs_login.open sql, conn, adopenkeyset, adlockpessimistic if rs_login.eof = true then msgbox "没有这个用户,请重输入！", vbokonly + vbexclamation, "" text1.text = "" text1.setfocus else username = text1.text if trim(rs_login.fields(1)) = trim(text2.text) then unload me 图书馆理系统.show else msgbox "密码不正确,请重输入！", vbokonly + vbexclamation, "" text2.setfocus text2.text = "" end if end if end if cnt = cnt + 1 if cnt = 3 then unload me end if end sub private sub form_load() cnt = 0 end sub