Sql 从另一个联接子查询中的联接引用列

我正试图用连接、子查询和agregate函数编写一个有点复杂的POSTGRES查询。除了一件事，一切都很好。代码如下：

SELECT 

table1.id AS id1,
table1.name AS name,
table1.table2_fkey AS id2
table2.name AS name2,
table2.id,
month_sum

FROM table1 
LEFT JOIN table2 ON (table1.table2_fkey = table2.id) 
INNER JOIN (
    SELECT sum(months) AS month_sum FROM (
        SELECT (month_1 + month_2 + month_3 + month_4 + month_5 + month_6 + month_7 + month_8 + month_9 + month_10 + month_11 + month_12) as months FROM table2_places_years WHERE table2_places_fkey IN (
            SELECT id FROM table2_places WHERE table2_people_fkey IN (
                SELECT id FROM table2_people WHERE table2_fkey = table2.id
            )
        ) 
    ) AS months
) AS month_sum ON (table2.id = id2)

（i简化了列和表的名称）

问题是，第二个联接中的最后一个子查询无法从第一个联接访问table2，所以它会抛出一个错误。如果我从最后一个子查询中删除where子句，查询运行正常，但会得到“table2\u places\u years”中所有行的总和。我只需要与表2中的当前条目相关联的行的总和（通过另外三个表与FKEY链接）

有没有办法让子查询知道第一个join子句中的列

提前谢谢

---

注意：这段代码可能无法工作，因为我做了一些简化。

如果数据允许，请使用联接重写查询。然后它会像这样：

join (
select table2_fkey, sum(…) …
from table2_places_years
join table2_places …
join table2_people …
group by table2_fkey
) month_sum on table2_fkey = table2.id

SELECT 

table1.id AS id1,
table1.name AS name,
table1.table2_fkey AS id2
table2.name AS name2,
table2.id,
month_sum

FROM table1 
LEFT JOIN table2 ON (table1.table2_fkey = table2.id),
LATERAL (
    SELECT sum(months) AS month_sum FROM (
        SELECT (month_1 + month_2 + month_3 + month_4 + month_5 + month_6 + month_7 + month_8 + month_9 + month_10 + month_11 + month_12) as months FROM table2_places_years WHERE table2_places_fkey IN (
            SELECT id FROM table2_places WHERE table2_people_fkey IN (
                SELECT id FROM table2_people WHERE table2_fkey = table2.id
            )
        ) 
    ) AS months
) month_sum

如果没有，还可以将相关子查询放置在select语句中：

select …,
      (
      select sum(…) …
      ) month_sum
from table1 left join table2 …

最后一种方法可能是横向连接。可能是这样的：

join (
select table2_fkey, sum(…) …
from table2_places_years
join table2_places …
join table2_people …
group by table2_fkey
) month_sum on table2_fkey = table2.id

SELECT 

table1.id AS id1,
table1.name AS name,
table1.table2_fkey AS id2
table2.name AS name2,
table2.id,
month_sum

FROM table1 
LEFT JOIN table2 ON (table1.table2_fkey = table2.id),
LATERAL (
    SELECT sum(months) AS month_sum FROM (
        SELECT (month_1 + month_2 + month_3 + month_4 + month_5 + month_6 + month_7 + month_8 + month_9 + month_10 + month_11 + month_12) as months FROM table2_places_years WHERE table2_places_fkey IN (
            SELECT id FROM table2_places WHERE table2_people_fkey IN (
                SELECT id FROM table2_people WHERE table2_fkey = table2.id
            )
        ) 
    ) AS months
) month_sum

---

如果数据允许，请使用联接重写查询。然后它会像这样：

join (
select table2_fkey, sum(…) …
from table2_places_years
join table2_places …
join table2_people …
group by table2_fkey
) month_sum on table2_fkey = table2.id

SELECT 

table1.id AS id1,
table1.name AS name,
table1.table2_fkey AS id2
table2.name AS name2,
table2.id,
month_sum

FROM table1 
LEFT JOIN table2 ON (table1.table2_fkey = table2.id),
LATERAL (
    SELECT sum(months) AS month_sum FROM (
        SELECT (month_1 + month_2 + month_3 + month_4 + month_5 + month_6 + month_7 + month_8 + month_9 + month_10 + month_11 + month_12) as months FROM table2_places_years WHERE table2_places_fkey IN (
            SELECT id FROM table2_places WHERE table2_people_fkey IN (
                SELECT id FROM table2_people WHERE table2_fkey = table2.id
            )
        ) 
    ) AS months
) month_sum

如果没有，还可以将相关子查询放置在select语句中：

select …,
      (
      select sum(…) …
      ) month_sum
from table1 left join table2 …

最后一种方法可能是横向连接。可能是这样的：

join (
select table2_fkey, sum(…) …
from table2_places_years
join table2_places …
join table2_people …
group by table2_fkey
) month_sum on table2_fkey = table2.id

SELECT 

table1.id AS id1,
table1.name AS name,
table1.table2_fkey AS id2
table2.name AS name2,
table2.id,
month_sum

FROM table1 
LEFT JOIN table2 ON (table1.table2_fkey = table2.id),
LATERAL (
    SELECT sum(months) AS month_sum FROM (
        SELECT (month_1 + month_2 + month_3 + month_4 + month_5 + month_6 + month_7 + month_8 + month_9 + month_10 + month_11 + month_12) as months FROM table2_places_years WHERE table2_places_fkey IN (
            SELECT id FROM table2_places WHERE table2_people_fkey IN (
                SELECT id FROM table2_people WHERE table2_fkey = table2.id
            )
        ) 
    ) AS months
) month_sum

---

谢谢！我必须使用postgres 8.4，所以横向连接不是一个选项（但感谢您提供了一个关于学习的好提示：-）），而且实际数据不允许使用第一个选项，所以最好的选择是第二个。我将研究相关的子查询（到目前为止还不知道），并在这里发布一个完整的解决方案。再次感谢！谢谢我必须使用postgres 8.4，所以横向连接不是一个选项（但感谢您提供了一个关于学习的好提示：-）），而且实际数据不允许使用第一个选项，所以最好的选择是第二个。我将研究相关的子查询（到目前为止还不知道），并在这里发布一个完整的解决方案。再次感谢！