select Table1.ID,Table1.Code,Table1.Name,case when T2.id is not null then 1 else 0 end as number from Table1 T1 left join Table2 T2 on T1.id=T2.id group by Table1.ID,Table1.Code,Table1.Name
select T1.ID,T1.Code,T1.Name,case when T2.id is not null then 1 else 0 end as number from Table1 T1 left join Table2 T2 on T1.id=T2.id group by T1.ID,T1.Code,T1.Name
select a.id,a.code,a.name,count(b.id) as count from table1 a,table2 b where a.id *= b.id group by a.id,a.code,a.name
不好意思!没仔细看 上面的写错了! select T1.ID,T1.Code,T1.Name,sum(case when T2.id is not null then 1 else 0 end)as number from Table1 T1 left join Table2 T2 on T1.id=T2.id group by T1.ID,T1.Code,T1.Name
select t1.ID,t1.Code,t1.Name ,count(1) from table1 t1 join table2 t2 on t2.ID= t1.ID group t1.ID,t1.Code,t1.Name
from Table1 T1
left join
Table2 T2 on T1.id=T2.id
group by T1.ID,T1.Code,T1.Name
from table1 a,table2 b
where a.id *= b.id
group by a.id,a.code,a.name
select T1.ID,T1.Code,T1.Name,sum(case when T2.id is not null then 1 else 0 end)as number
from Table1 T1
left join
Table2 T2 on T1.id=T2.id
group by T1.ID,T1.Code,T1.Name
join table2 t2 on t2.ID= t1.ID
group t1.ID,t1.Code,t1.Name