基本上，我想这样做:
update vehicles_vehicle v
join shipments_shipment s on v.shipment_id=s.id
set v.price=s.price_per_vehicle;
我很确定这在MySQL(我的背景)中可以工作，但在postgres中似乎不起作用。我得到的错误是:
ERROR: syntax error at or near "join"
LINE 1: update vehicles_vehicle v join shipments_shipment s on v.shi...
^
当然有一个简单的方法来做到这一点，但我找不到合适的语法。那么，我该如何在PostgreSQL中写这个呢?
当前回答
UPDATE语法为:
[ WITH [ RECURSIVE ] with_query [, ...] ]
UPDATE [ ONLY ] table [ [ AS ] alias ]
SET { column = { expression | DEFAULT } |
( column [, ...] ) = ( { expression | DEFAULT } [, ...] ) } [, ...]
[ FROM from_list ]
[ WHERE condition | WHERE CURRENT OF cursor_name ]
[ RETURNING * | output_expression [ [ AS ] output_name ] [, ...] ]
在你的情况下，我认为你想要的是:
UPDATE vehicles_vehicle AS v
SET price = s.price_per_vehicle
FROM shipments_shipment AS s
WHERE v.shipment_id = s.id
或者如果你需要连接两个或多个表:
UPDATE table_1 t1
SET foo = 'new_value'
FROM table_2 t2
JOIN table_3 t3 ON t3.id = t2.t3_id
WHERE
t2.id = t1.t2_id
AND t3.bar = True;
其他回答
对于那些想要做一个JOIN，更新你的连接返回行使用:
UPDATE a
SET price = b_alias.unit_price
FROM a AS a_alias
LEFT JOIN b AS b_alias ON a_alias.b_fk = b_alias.id
WHERE a_alias.unit_name LIKE 'some_value'
AND a.id = a_alias.id
--the below line is critical for updating ONLY joined rows
AND a.pk_id = a_alias.pk_id;
这是上面提到的，但只是通过一个评论..因为它是至关重要的，以获得正确的结果张贴新的答案，工作
开始吧:
update vehicles_vehicle v
set price=s.price_per_vehicle
from shipments_shipment s
where v.shipment_id=s.id;
我能做到的最简单。
完美的工作! !
带有JOIN的POSTGRE SQL - UPDATE
下面代码-检查列和id的定位如下:
如果你把它放在下面，那么只有它会工作!
---IF you want to update FIRST table
UPDATE table1
SET attribute1 = table2.attribute1
FROM table2
WHERE table2.product_ID = table1.product_ID;
OR
---IF you want to update SECOND table
UPDATE table2
SET attribute1 = table1.attribute1
FROM table1
WHERE table1.product_ID = table2.product_ID;
第一个表名:tbl_table1 (tab1)。 第二表名:tbl_table2 (tab2)。
将tbl_table1的ac_status列设置为“INACTIVE”
update common.tbl_table1 as tab1
set ac_status= 'INACTIVE' --tbl_table1's "ac_status"
from common.tbl_table2 as tab2
where tab1.ref_id= '1111111'
and tab2.rel_type= 'CUSTOMER';
对于那些真正想要做JOIN的人，你也可以使用:
UPDATE a
SET price = b_alias.unit_price
FROM a AS a_alias
LEFT JOIN b AS b_alias ON a_alias.b_fk = b_alias.id
WHERE a_alias.unit_name LIKE 'some_value'
AND a.id = a_alias.id;
如果需要，可以在等号右侧的SET部分中使用a_alias。 等号左边的字段不需要表引用，因为它们被认为来自原始的“a”表。
