Hive 如何向此配置单元命令添加更多表？

此查询用于从两个表（表1和表2）中获取内容，这两个表是来自不同表的不同字段。如果我想从另一个表中获得一个字段，表3以相同的“mid”字段为条件，我是否应该将查询更改为以下形式：

dt1=$1
  
desfile="data_$dt1"
 hql="
 select DISTINCT b.mid, b.create_time, d.content from
     (select mid, create_time, to_id, dt from table_1 where dt>=$dt1 and to_id='1042015' ) b
  join
      (select mid, content from table_2 where dt>=$dt1) d
  on(b.mid=d.mid)
 "
  
 hive -e "$hql"> $desfile
  

---

不能同时联接所有三个表，但应先联接b和d，然后再联接a

hql="
     select DISTINCT a.off_time, b.mid, b.create_time, d.content from
         (select mid, create_time, to_id, dt from table_1 where dt>=$dt1 and to_id='1042015' ) b
      join
          (select mid, content from table_2 where dt>=$dt1) d
      join 
          (select mid, off_time from table_3 where dt>=dt1) a
      on(b.mid=d.mid=a.mid)
     "

select DISTINCT a.off_time, b.mid, b.create_time, d.content from
         (select mid, create_time, to_id, dt from table_1 where dt>=$dt1 and to_id='1042015') b
      join
          (select mid, content from table_2 where dt>=$dt1) d
      on(b.mid = d.mid)
      join 
          (select mid, off_time from table_3 where dt>=$dt1) a
      on(b.mid = a.mid)