如何在 PostgreSQL 9.2.13 中执行 *此特定 * 更新 + 加入？

Question

好的。我知道这个用例already has a question devoted to it here，但我已经尝试过那里的任何语法，但我越来越绝望了。

这是我的查询：

with ids as (
  select t.id ntid, ot.id otid, p.id npid, op.id opid, ot.company_id ocid, t.company_id ncid
  from product_template t
  inner join product_template ot on t.multicompany_old_id = ot.id
  inner join product_product p on p.product_tmpl_id = t.id
  inner join product_product op on op.product_tmpl_id = ot.id
)
update ol
set product_id = i.npid
from sale_order_line ol
inner join sale_order o on ol.order_id = o.id
inner join product_product p on ol.product_id = p.id
inner join ids i on p.id = i.opid and o.company_id = i.ncid;

我尝试过的变体：

update [sale_order_line] ol
set [ol.]product_id = i.npid
from...

update sale_order_line ol
set ol.product_id = i.npid
inner join ....

update sale_order_line ol
set product_id = i.npid
from sale_order o on ol.order_id = o.id
inner join product_product p on ol.product_id = p.id
inner join ids i on p.id = i.opid and o.company_id = i.ncid
where ol.order_id = o.id;

没有任何作用。有人可以帮助我吗？ 我想以下简化案例的解决方案也足够了：

update T
set T.value = J.value
from some_table T
inner join joined_table J on J.some_table_id = T.id;

Answer 1

试试这个：

WITH ids AS (
    SELECT
        t.id ntid,
        ot.id otid,
        p.id npid,
        op.id opid,
        ot.company_id ocid,
        t.company_id ncid
    FROM product_template t
        INNER JOIN product_template ot ON t.multicompany_old_id = ot.id
        INNER JOIN product_product p ON p.product_tmpl_id = t.id
        INNER JOIN product_product op ON op.product_tmpl_id = ot.id
)
UPDATE sale_order_line
SET product_id = i.npid
FROM sale_order_line ol
    INNER JOIN sale_order o ON ol.order_id = o.id
    INNER JOIN product_product p ON ol.product_id = p.id
    INNER JOIN ids i ON p.id = i.opid AND o.company_id = i.ncid
WHERE sale_order_line.id = ol.id;

这个想法是您要更新的表在FROM 部分之外，并且要进行更新，您需要标记在哪些情况下您需要使用WHERE 部分更新数据。

Answer 2

您不需要将更新中的 target 表添加/加入到FROM // 'JOIN' 列表中；它已经在范围表中。

WITH ids AS (
  SELECT t.id ntid, ot.id otid, p.id npid
        , op.id opid, ot.company_id ocid, t.company_id ncid
  FROM product_template t
  JOIN product_template ot ON t.multicompany_old_id = ot.id 
  JOIN product_product p ON p.product_tmpl_id = t.id
  JOIN product_product op ON op.product_tmpl_id = ot.id 
)
UPDATE sale_order_line ol -- <<-- target table has an alias
SET product_id = i.npid   -- <<-- product_id SHOULD NOT use this alias
FROM ids i 
JOIN sale_order o ON o.company_id = i.ncid;
JOIN product_product p ON p.id = i.opid
WHERE ol.product_id = p.id   -- <<-- target table is linked    
AND ol.order_id = o.id       -- <<-- to the source(s) here
        ;