临时表还是清晰一点 with tmp as( select user_id, sum(grade_num) total_num from grade_info group by user_id order by total_num desc limit 1 ) select user.name, tmp.total_num grade_num from tmp,user where user.id=tmp.user_id点
我都不知道我在写什么了 with tmp as( select user_id from order_info where date >'2025-10-15' and product_name in ('c++','python','java') and status = 'completed' group by user_id having count(*) > 1 ) # select * from tmp select o.id, is_group_buy, ( case when is_group...
with as的用法可以通俗点讲是,讲需要频繁执行的slq片段加个别名放到全局中,后面直接调用就可以,这样减少调用次数,优化执行效率。 语法: 针对一个别名 with tmp as (select * from tb_name) 针对多个别名 with tmp as (select * from tb_name), tmp2 as (select * from tb_name2), tmp3 as (select *...
tmp as (select * from tb_name), tmp2 as (select * from tb_name2), tmp3 as (select * from tb_name3), … 1 2 3 4 5 6 7 8 9 --相当于建了个e临时表 witheas(select*fromscott.emp ewheree.empno=7499) select*frome; --相当于建了e、d临时表 with eas(select*fromscott.emp),...
3.在同级select前有多个查询定义的时候,第1个用with,后面的不用with,并且用逗号隔开。 4.最后一个with 子句与下面的查询之间不能有逗号,只通过右括号分割,with 子句的查询必须用括号括起来 用法: –针对一个别名 with tmp as (select * from tb_name) ...
with tmp(a) as (select 1 union all select 2) select * from tmp; 正巧之前客户就咨询我,WITH 有没有可能和 UPDATE、DELETE 等语句一起来用?或者说有没有可以简化日常 SQL 的其他用法,有点迷惑,能否写几个例子简单说明下? 其实WITH 表达式除了和 SELECT 一起用, 还可以有下面的组合: ...
with tmp as (select * from tb_name), tmp2 as (select * from tb_name2), tmp3 as (select * from tb_name3), 1、基础认知 ▶with as短语,也叫做子查询部分(subquery factoring)。并不是真正的临时表,查询结果保存在内存中。 ▶后面必须直接紧跟使用with as的SQL语句,否则失效 ▶适用于:为了...
select behavior,count(distinct user_id) as userCnt from user_behavior where behavior='buy' group by behaviorunion all select behavior,count(1) as userCnt from user_behavior where behavior='cart' group by behavior;复制代码 1. with tmp as (select user_id,behavior from user_behavior where behavi...
我觉得你的sql写的有问题，就是你with tmp sql的问题——该回答整理自钉群“【③群】Apache Flink ...
看起来使用with...as...语句反而更复杂一点,但如果tmp_shanghai要被多次使用的使用,就很有必要 来看一个实际的例子,有一张操作表event主要字段如下: ... 现在要求一条sql统计出Get与Set操作的数量,先使用子查询实现 select(selectcount(*)fromeventwhereevent_key="Get")asget_num,(selectcount(*)fromevent...