Storage Pool的起源 ========================== Some time ago, EMC introduced the concept of Virtual Provisioning and Storage Pools in their Clariion line of arrays. The main idea for doing this is to make management for the storage admin simple. The trad…
在sql中,如果有group by,那么select的字段只能包含分组内容,或者count.sum.avg这些统计字段. 但在linq里面,是:group 你想要什么字段 by 分组字段 比如: var q = from p in db.Products group p by p.CategoryID into g select g; 实际应用中,多表多字段参与分组比较常见: from a in TableA join b in TableB on a.Id equals b.aId || b.…
//Line to Sql 写法 var data = (from a in Items group a by new { a.GroupId, a.Id } into b //orderby new ComparerItem() { GroupId = b.Key.GroupId, Id = b.Key.Id } descending .where(o => o.Id>1000) select new { GroupId = b.Key.GroupId, Id = b.Key.Id, Cou…
使用group by 需要查询的字段 必须要放在group by 后面 SELECT U.UserLotterySn,count(W.Userlotterysn) as WinCount,U.ActivityCode,CertType,CertNumber,LotterySumCount,LotteryCounted,IsBigWin,U.CreateBy,U.CreateDateFROM T_UserLottery U JOIN T_WinningUser W on W.UserLottery…
1. 复制表结构及其数据: create table table_name_new as select * from table_name_old 2. 只复制表结构: create table table_name_new as select * from table_name_old where 1=2; 或者: create table table_name_new like table_name_old 3. 只复制表数据: 如果两个表结构一样: insert into table_na…
