《prb: implicit connections created by the sql server ole db provider (sqloledb) are not pooled》
【不会重复建立数据库连接的代码片断】：
通过改变ado.recordset的属性避免隐式登录
dim cn as new adodb.connection
dim rs as new adodb.recordset
dim rs2 as new adodb.recordset
cn.open ..........
rs.cursortype = adopenstatic
rs.activeconnection = cn
rs.open "select * from orders"
rs.cursortype = adopenstatic
rs2.activeconnection = cn
