sql 联合查询子表时间最新的数据

主表：

table1 (uniqueid,name)

table2(uniqueid,tbl1_uniqueid,loginTime)

table1 数据

uniqueid  name

1               张三

2               李四

3               王武

table2 数据

uniqueid    tbl1_uniqueid     loginTime

1                  1                            2015-7-12

2                  1                            2015-7-15

3                  1                            2015-7-21

4                  2                            2015-7-9

查询结果为：

uniqueid     name      loginTime

1                  张三         2015-7-21

2                  李四          2015-7-9

sql语句为：

select a.uniqueid as uniqueid ,a.name as name ,b.loginTime as loginTime 
from table1 as a
left join
table2 as b 
on a.uniqueid = b.tbl1_uniqueid
where b.loginTime in (select max(loginTime) from table2 group by tbl1_uniqueid)