select * from t1 join t2 on t1.model=t2.model where t1.model='001'
select MODEL from tb1 where MODEL='001' union all select MODEL from tb2 where MODEL='001' ;
select * from t1 , t2 where t1.model=t2.model and t1.model='001'
select t1.*,t2.* from t1 , t2 where t1.model=t2.model and t2.model='001'
select model from t1 where model='001' union all select model from t2 where model='001'
那要是三个表怎么写,我想显示出MODEL,ID这两个字段
三张表select m1.model,m1.id from model m1,model m2,model m3 where m1.model = m2.model and m1.model = m3.model
select m1.model,m1.id from model m1,model m2,model m3 where m1.model = m2.model and m1.model = m3.model and m1.model = '001' 忘加001了.寒.
.... 没必要吧。 我认为这样好点:select tb1.ID,tb1.Model from tb1 inner join tb2 on tb1.Model=tb2.Model inner join tb3 on tb1.Model = tb3.Model 如果多个表就多加一段就是!
对了,在加个查询条件:select tb1.ID,tb1.Model from tb1 inner join tb2 on tb1.Model=tb2.Model inner join tb3 on tb1.Model = tb3.Model where tb1.Model='001'
select HANDTRUCKS.ID,HANDTRUCKS.Model from HANDTRUCKS inner join CASTORS on HANDTRUCKS.Model=CASTORS.Model inner join WHEELBARROWS on HANDTRUCKS.Model=WHEELBARROWS.Model where HANDTRUCKS.Model='11' 哪里有问题呀?
select MODEL
from tb1
where MODEL='001'
union all
select MODEL
from tb2
where MODEL='001'
;
where t1.model=t2.model and t1.model='001'
where t1.model=t2.model and t2.model='001'
from t1
where model='001'
union all
select model
from t2
where model='001'
model m1,model m2,model m3
where m1.model = m2.model and m1.model = m3.model
select m1.model,m1.id from
model m1,model m2,model m3
where m1.model = m2.model and m1.model = m3.model
and m1.model = '001'
忘加001了.寒.
没必要吧。
我认为这样好点:select tb1.ID,tb1.Model from tb1 inner join tb2 on
tb1.Model=tb2.Model inner join tb3 on tb1.Model = tb3.Model
如果多个表就多加一段就是!
tb1.Model=tb2.Model inner join tb3 on tb1.Model = tb3.Model
where tb1.Model='001'
哪里有问题呀?