sql 笔记

分组

case when 1

select distinct a.Branch,
case when kultur = '硕士' then sum(num) else '0' end as 研究生学历,
case when kultur = '本科' then sum(num) else '0' end as 大本学历,
case when kultur = '大专' then sum(num) else '0' end as 大专学历,
case when kultur = '中专' then sum(num) else '0' end as 中专学历,
case when kultur = '高中' or kultur ='职高' or kultur ='中职'  then sum(num) else '0' end as 高中学历,
case when kultur = '初中' then sum(num) else '0' end as 初中学历,
case when kultur = '小学' then sum(num) else '0' end as 小学学历,
case when kultur = '' or kultur is null  then sum(num) else '0' end as 未填写学历
from( select Branch,kultur,count(*) as num 
        from tb_Stuffbusic 
     group by branch,kultur) a
Group by a.Branch,a.kultur

case when 2

select Branch as 部门名称,count(branch) as 总人数,
sum(case when kultur = '硕士' then 1 else '0' end) as 研究生学历,
sum(case when kultur = '本科' then 1 else '0' end) as 大本学历,
sum(case when kultur = '大专' then 1 else '0' end) as 大专学历,
sum(case when kultur = '中专' then 1 else '0' end) as 中专学历,
sum(case when kultur = '高中' or kultur ='职高' or kultur ='中职'  then 1 else '0' end) as 高中学历,
sum(case when kultur = '初中' then 1 else '0' end) as 初中学历,
sum(case when kultur = '小学' then 1 else '0' end) as 小学学历,
sum(case when kultur = '' or kultur is null  then 1 else '0' end) as 未填写学历
from tb_Stuffbusic         
group by branch

case when 3

UPDATE tb_Stuffbusic
SET ID = CASE WHEN LEN(ID) = 1 THEN '000'+ID
              WHEN LEN(ID) = 2 THEN '00'+ID
              WHEN LEN(ID) = 3 THEN '0'+ID
              ELSE ID
              END

partition by

select * from
        (
          SELECT 
                ROW_NUMBER() over(partition by [姓名] order by [打卡时间] desc) as rowNum
              ,[姓名]
              ,[打卡时间]
          FROM [dbo].[打卡记录表]
        ) temp
        where temp.rowNum = 1