select personid,年龄、habit ,物品 from toys,habit where toys.personid=habit.personid
1, select a.*,b.toysCount from 人表 a left join (select personid,count(*) as toysCount from toys group by personid) b on a.personid=b.personid 2,select a.*,b.toysCount,c.* from 人表 a left join (select personid,count(*) as toysCount from toys group by personid) b on a.personid=b.personid left join habit on a.personid=c.habit
select a.personid,年龄,tmp_counts from 人表,(select personid,count(物品) as tmp_counts from 物品表 group by personid) as b where a.personid=b.personid
create table person ( personid varchar(2),person varchar(40)) create table personwp (personid varchar(2),personwp varchar(40))insert into person values('1','songc') insert into person values('2','huanghb')insert into personwp values ('2','手机') insert into personwp values('1','电视') select person.personid ,count(personwp.personwp) from person left join personwp on person.personid=personwp.personid group by person.personid 你要的就是最后一条语句!保证没有问题,我在查询器中用过了!
from toys,habit
where toys.personid=habit.personid
select a.*,b.toysCount from 人表 a left join
(select personid,count(*) as toysCount from toys group by personid) b
on a.personid=b.personid
2,select a.*,b.toysCount,c.* from 人表 a left join
(select personid,count(*) as toysCount from toys group by personid) b
on a.personid=b.personid
left join habit on a.personid=c.habit
from 人表,(select personid,count(物品) as tmp_counts from 物品表 group by personid) as b
where a.personid=b.personid
create table personwp (personid varchar(2),personwp varchar(40))insert into person values('1','songc')
insert into person values('2','huanghb')insert into personwp values ('2','手机')
insert into personwp values('1','电视') select person.personid ,count(personwp.personwp) from person left join personwp on person.personid=personwp.personid group by person.personid
你要的就是最后一条语句!保证没有问题,我在查询器中用过了!