问答题

求出小于45岁的各个老师所带的大于12岁的学生人数


实验数据:

drop table if exists tea_stu;

drop table if exists teacher;

drop table if exists student;

 

create table teacher(

teaID int primary key,

name varchar(50),

age int

);

 

create table student(

stuID int primary key,

name varchar(50),

age int

);

 

create table tea_stu(

teaID int references teacher(teaID),

stuID int references student(stuID)

);

 

insert into teacher values (1,'zxx',45),  (2,'lhm',25) ,  (3,'wzg',26) ,  (4,'tg',27);

insert into student values (1,'wy',11),  (2,'dh',25) ,  (3,'ysq',26) ,  (4,'mxc',27);

insert into tea_stu values (1,1),  (1,2),  (1,3);

insert into tea_stu values (2,2),  (2,3),  (2,4);

insert into tea_stu values (3,3),  (3,4),  (3,1);

insert into tea_stu values (4,4),  (4,1),  (4,2),  (4,3);


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