where后条件或者部分条件移到了case when后面,那么sql的计算数据集就会变大,where条件后的全部数据都要参与case when的指标计算,这就会造成不满足条件的数据也会进行计算,如果有group by的情况,可能某一个分组的指标数据都是0 3、条件表达式放在where后面,这样可以提高性能,但是同时也限制了其他维度指标的计算;条件或者...
CASE WHEN pref_name in ('德岛', '香川', '爱媛', '高知') THEN '九州' WHEN pref_name in ...
WHEN score>=85 THEN "优秀" ELSE "未知" END AS "阶段" ,count(DISTINCT a.s_id) as "包含人数" from score a INNER JOIN student b on a.s_id=b.s_id GROUP BY CASE WHEN score<60 THEN "不及格" WHEN score>=60 and score<85 THEN "良" WHEN score>=85 THEN "优秀" ELSE "未知" ...
SELECT (CASE WHEN c.in_force_dateISNOT NULL THEN (CASE WHEN a.mio_date>=c.in_force_dateTHENa.mio_date ELSE c.in_force_date END ) WHEN c.in_force_dateISNULL THEN (CASE WHEN a.mio_date>=a.plnmio_dateTHENa.mio_date ELSE a.plnmio_date END ) ELSE a.mio_date END ) mio_date...
今天提交程序之后,反应有BUG,经仔细查询,发现一个之前并没注意到的问题,那就是case when 语句在Oracle中执行的BUG,用脚本来说明; Oracle --建表 CREATE TABLE TABLE_01 (CODE INT NOT NULL, NAME VARCHAR2(20) NULL); --插入数值,之所以分别插入null和''是因为在Sybase中''和null是... ...
WHEN，就等于是问OQL如何支持CASE WHEN了。 这个问题已经不止这一个朋友来问我了，我想了下 ...
' when b.plan_type=2 then '个人计划' else '' end) as planSource, orderid from trainee_info a LEFT JOIN trainee_rotation_program b on (a.group_id = b.group_id or b.trainee_id=a.id) left join trainee_group_info g on b.group_id = g.id LEFT JOIN org_structure c on b.dept...
WHEN c.in_force_dateISNULLTHEN (CASE WHEN a.mio_date>=a.plnmio_dateTHENa.mio_date ELSE a.plnmio_date END ) ELSE a.mio_date END ) mio_date FROM dbo.mio_loga INNERJOIN dbo.freph_a01_fromtask3c ON a.cntr_no = c.cntr_no ...
--创建测试表IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[TB]') AND type in (N'U'))DROP TABLE [dbo].[TB1]GOCREATE TABLE [dbo].[TB1]( [卡状态] [nvarchar] (20) NULL, [卡类型] [nvarchar](50) NULL,) ON [PRIMARY]GO--插入...
case when t.bk2='on' then 1 else 0 end + case when t.bk3='on' then 1 else 0 end as 总合 from info t order by 总合 desc Case具有两种格式。简单Case函数和Case搜索函数。 --简单Case函数 CASE sex WHEN '1' THEN '男' WHEN '2' THEN '女' ...