我问了一个问题，得到了这个有用的回答。
UPDATE TABLE_A a JOIN TABLE_B b
ON a.join_col = b.join_col AND a.column_a = b.column_b
SET a.column_c = a.column_c + 1
现在，如果有三个表涉及到这样的东西，我希望这样做。
UPDATE tableC c JOIN tableB b JOIN tableA a
我的问题基本上是…有可能在一个UPDATE语句上做三个表连接吗?它的正确语法是什么?
我要做以下事情吗?
JOIN tableB, tableA
JOIN tableB JOIN tableA
当前回答
是的，您可以为更新语句执行三表连接。这里有一个例子:
UPDATE customer_table c
JOIN
employee_table e
ON c.city_id = e.city_id
JOIN
anyother_ table a
ON a.someID = e.someID
SET c.active = "Yes"
WHERE c.city = "New york";
其他回答
没有一个答案不适合我，我在mysql手册上找到了这个
UPDATE T1,T2 INNER JOIN T2 ON T1.C1 = T2.C1 SET T1.C2 = T2.C2, T2.C3 = expr WHERE condition
是的，您可以为更新语句执行三表连接。这里有一个例子:
UPDATE customer_table c
JOIN
employee_table e
ON c.city_id = e.city_id
JOIN
anyother_ table a
ON a.someID = e.someID
SET c.active = "Yes"
WHERE c.city = "New york";
PostgreSQL的例子:
UPDATE TableA AS a
SET param_from_table_a=FALSE -- param FROM TableA
FROM TableB AS b
WHERE b.id=a.param_id AND a.amount <> 0;
下面是包含JOIN和WHERE的更新查询。同样，我们可以使用多个join/where子句:
UPDATE opportunities_cstm oc JOIN opportunities o ON oc.id_c = o.id
SET oc.forecast_stage_c = 'APX'
WHERE o.deleted = 0
AND o.sales_stage IN('ABC','PQR','XYZ')
备选的总体规划:
UPDATE table A
JOIN table B ON {join fields}
JOIN table C ON {join fields}
JOIN {as many tables as you need}
SET A.column = {expression}
例子:
UPDATE person P
JOIN address A ON P.home_address_id = A.id
JOIN city C ON A.city_id = C.id
SET P.home_zip = C.zipcode;
