select case when 判断时间 = '2011-01-15' then 'OK' else 'KO' END AS 时间判断 from tab case when... else .. end--->根据条件判断 as 时间判断--->给列起了个别名。
可以。例如：user表中有id,name,sex三个字段 select case when (select count(id) from user where sex='男')>10 then '男人有10人以上'else '10人以内' end as count from user;
CASE WHEN o.order_total >= 100 THEN "超过100元" WHEN o.order_total <= 50 THEN "低于50元" ELSE "未知" END AS order_status FROM orders o ``` 在上面的示例中,我们使用`select case`语句来选择订单的状态。在`case`块中,我们比较订单总金额和阈值,并根据结果选择状态。如果总金额超过100元,则...
SELECT Id, Category, Name, CASE When(Category = 'Animal') Then Property1_Value ELSE NULL END AS Age, CASE When(Category = 'Book') Then Property1_Value ELSE NULL END AS Price From CateogoryDetail 大功告成。 1. 2. 3. 用例二: USE pubs GO SELECT Title, 'Price Range' = CASE WHEN ...
6,1003);3、查询表中数据，select * from test_student ,4、编写case when 表达式，将class_id翻译为中文名称，sql如下，select t.*,case when class_id = 1001 then '语文'when class_id = 1002 then '数学'when class_id = 1003 then '英语'end as class_name from test_student t;...
END GO 你甚至还可以组合这些选项,添加一个ORDERBY子句,如下所示: USEpubs GO SELECT CASE WHENpriceISNULLTHEN'Unpriced' WHENprice<10THEN'Bargain' WHENpriceBETWEEN10and20THEN'Average' ELSE'Gift to impress relatives' ENDASRange, Title FROMtitles ...
SQL 条件 判断 select case as selectcasewhenstring="1"then"返回的数据1"whenstring="2"then"返回的数据2"else"返回的其他数据"endas新的列名fromtablewhere...
END AS vt FROM sdc_dw.fm_vessel 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 除了应用在select返回外,case when能否用在from或where呢?带着这个疑问,做了下面几个测试。 测试1:动态from select * from case when 1=1 then ...
因为你用了 else null end, 也就是出来3类 销售笔数，同期销售笔数，null,把这句删了就可以了 修改如下 select case when to_date(to_char(shdate,'yyyy-mm-dd'),'yyyy-mm-dd')= to_date(to_char(sysdate-1,'yyyy-mm-dd'),'yyyy-mm-dd') then '销售笔数'when to_date(to_char(...
在执行SELECT语句时为CASE指定别名,可以通过使用AS关键字来为CASE语句指定别名。CASE语句用于在查询结果中根据条件进行条件判断和返回不同的值。 下面是一个示例: 代码语言:sql 复制 SELECT column_name, CASE WHEN condition1 THEN result1 WHEN condition2 THEN result2 ELSE result3 END AS alias_name FROM table...