高级 sql 常用语法总结

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1. sql 统计总结: https://www.cnblogs.com/snake-hand/p/3181728.html,例子: 统计所有员工的业绩

   select s.Email,SUM(cast(ach.Paid as money))  from
   (select * from T_Staff where State=1) as s
   left join T_Achievement as ach on ach.SaleUser_ID=s.ID
   where ach.Null2='2022-1'
   group by all s.Email
   

   　　

2. 递归查询，适合自循环级联查询

   with cte as(
   select NO,Null4 from T_Contract where No='X21-87'
   union all 
   select a.No,a.Null4 from T_Contract as a
   inner join cte as b
   on b.Null4=a.No
   )
   select No from cte

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