student表中有字段:sno.ssex,class,sname,sbirthday
course表中有字段:cno,cname,tno
score表中有字段:sno,cno,degree
teacher表中有字段:tno,tname,tsex,trof,tbirthday,depart查询所有教师和同学的name、sex和birthday.
course表中有字段:cno,cname,tno
score表中有字段:sno,cno,degree
teacher表中有字段:tno,tname,tsex,trof,tbirthday,depart查询所有教师和同学的name、sex和birthday.
uinon
select tname,tsex,tbirthday
union all
(select sname as name,seex as sex,sbirthday as birth from student)
union all
(select sname as name,seex as sex,sbirthday as birth,'老师' as diffe from student)
select sname as name,ssex as sex,sbirthday as birthday from student
uinon all
select tname,tsex,tbirthday from teacher
union all
select m.tname name , m.tsex sex , m.tbirthday birthday from teacher m