得到id集后算出Y1、Y2、Y3对应的三个id 最后 select * from t where id in 这样扫描的行数应该是C+Ymax+3mysql> select count into @C from t;
第74题refers to the management of the overall and long-term development direction objectives tasks and policies of an organization in a certain period，as well as the corresponding decisions on the organization's resource allocation，and the tracking， supervision and change of these decisions.
