SQLServer2005 中的几个统计技巧 |
 在SQLServer中我们可以用over子句中来代替子查询实现来提高效率,over子句除了排名函数之外也可以和聚合函数配合 。实现代码如下： 复制代码 代码如下: use tempdb go if (object_id (tb ) is not null ) drop table tb go create table tb (name varchar (10 ), val int ) go insert into tb select aa , 10 union all select aa , 20 union all select aa , 20 union all select aa , 30 union all select bb , 55 union all select bb , 45 union all select bb , 0 select * , 排名 = rank ()over (partition by name order by val ) , 占比 = cast (val * 1.0 / sum (val )over (partition by name ) as decimal (2 , 2 )) , 距最大 = val - max (val )over (partition by name ) , 距最小 = val - min (val )over (partition by name ) , 距平均 = val - avg (val )over (partition by name ) from tb |
