select sum(case when depart = 'Physical' then 1 else 0 end) PhyTotal, sum(case when depart = 'Chemistry' then 1 else 0 end) CheTotal, sum(case when depart = 'Math' then 1 else 0 end ) MathTotal from student…
case when 对表进行条件分组 case简单函数 case age when then select name , sex , age , ( case age /*when 条件成立显示then中内容 then 成立是显示 else 不成立显示 end*/ when age = 18 then '成年人' else '未成年' end when age = 30 then '而立之年' else '小伙子' end ) 身份 /*列名*/ from user name …
根据fileD6的前4位分组 分别统计该组 5种企业类型fileD31的数量 create or replace view jyjc_bycity as select substr(fileD6,1,4) site, count( case when fileD31 like '%国有%' then 1 end) numg, count( case when fileD31 like '%集体%' then 1 end) numj, count( case when fileD31 li…