A.對(duì)象B.隊(duì)列C.角色D.路由
A.權(quán)利B.數(shù)據(jù)C.安全D.限制
A.正相關(guān)子查詢B.相關(guān)子查詢C.非相關(guān)子查詢D.負(fù)相關(guān)子查詢