The MySQL CASE operator is demonstrated through an example where it returns "this is case one" when the CASE is 1. In another example, the operator returns "this is case two" when the CASE is 2. Table of contents How to use a case-when statement in a mysql stored procedure? MySQL OR...
sql中的case when 有点类似于Java中的switch语句,比较灵活,但是在Mysql中对于Null的处理有点特殊 Mysql中case when语法: 语法1: 1 2 3 4 5 CASE case_value WHEN when_value THEN statement_list [WHEN when_value THEN statement_list] ... [ELSE statement_list] END CASE 语法2: 1 2 3 4 5 CASE ...
CASE WHEN search_condition THEN statement_list [WHEN search_condition THEN statement_list] … [ELSE statement_list] END CASE 注意: 这两种语法是有区别的,区别如下: 1:第一种语法:case_value必须是一个表达式或字段名,例如 name或name is null等。 2:第二种语法CASE后面不需要变量或者表达式,直接执行时候...
case month(getdate()) when 11 then '十一' when 12 then '十二' else substring('一二三四...
mysql中casewhen用法 mysql中casewhen⽤法需求：需要在查询出的字段中，判断这个某个字段是否为null，并指定想要的值，SELECT temp.gId id,temp.`name`,temp.point,temp.give_user_proportion,temp.sales_price,temp.cover_img,temp.limit_num,temp.price,temp.show_sale_price,temp.isPromotion is_promotion F...
If you had done the same statement with an InnoDB table, they would have been delivered in PRIMARY KEY order, not INSERT order. Again, this is an artifact of the underlying implementation, not something to depend on. 对于innodb引擎表来说,在相同的情况下,select 不带order by,会根据主键来排序...
ApplicationofCase-wheninMySQL LIULei1,LINLi-dan2 (1.HenanPoliceCollege,Zhengzhou450000,China;2.LuoheVocationalTechnologyCollege,Luohe462000,China) Abstract:Intheactualresearchanddevelopmentwork,itisoftennecessarytowriteallkindsofSQLtostatisticallkindsofonlinebusinessdataortoperformdatafilteringoperationunderthecondit...
您不应在 WHEN 子句值中使用 NULL,因为如果执行,逻辑部分将为 NULL = NULL,结果为 FALSE。 现在对于 Search CASE,它遵循与 Simple CASE 相同的逻辑过程,但搜索案例的一部分使其执行起来有所不同。在这里,满足 MySQL 数据类型的值的 CASE 是基于它用于的上下文。例如,如果语句中使用了字符串上下文,则结果值将采...
[ELSE statement_list] END CASE;案例根据传入的月份,判定月份所属的季节(要求采用case结构)。1-3月份,为第一季度 4-6月份,为第二季度 7-9月份,为第三季度 10-12月份,为第四季度create procedure p(in month int) begin declare result varchar(10); case when month >= 1 and month <= 3 then set...
Category:MySQL Server: DMLSeverity:S3 (Non-critical) Version:8.0OS:Any Assigned to:CPU Architecture:Any Tags:case ... when,UPDATE [1 Feb 2024 10:50] yi qian Description:When using a subquery with a case when in the update statement, the updated data does not match the expected results ...