sql应用

最新推荐文章于 2025-11-24 14:11:55 发布

原创最新推荐文章于 2025-11-24 14:11:55 发布 · 307 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#sql #insert #table #join

create table tab_stu_info(stu_name varchar2(100), stu_school varchar2(100) );

insert into tab_stu_info values ('boy_john','001');
insert into tab_stu_info values ('boy_jim','002');
insert into tab_stu_info values ('gir_kate','001');
insert into tab_stu_info values ('gir_ann','003');

create table tab_school(sch_id varchar2(100), boy_pay int, gir_pay int);
insert into tab_school values ('001',33,19);
insert into tab_school values ('002',11,21);
insert into tab_school values ('003',22,32);

select stu_name,case when substr(stu_name,1,3)='boy' then boy_pay
else gir_pay end pay
from tab_stu_info inner join tab_school on stu_school=sch_id

就是说,从tab_stu_info中取出学生姓名和学校编号,靠姓名来判断学生的性别,然后靠学校编号和判断出来的性别,从tab_school中查出应该给此学生多少补助.