使用内部联接插入查询 [英] Insert query with an inner join

问题描述

我要进行插入查询，该查询具有对用户数据表的内部联接.

I want to make my insert query which has an inner join to a user's data table.

表的示例如下:

users:

uid | name 

---

users_data:

id | data_id | uid | other fields

---

data_stocks

id | data_id | quantity

---

因此，我试图插入data_stocks中，这仅与从users中了解uid有关.

---

So im trying to insert into data_stocks relating to only knowing the uid from users.

像这样的金达:

INSERT INTO data_stocks (data_id,quantity)
VALUES (' need to join it some how ','$quantity');

这在MySQL中可行吗?

Is this possible in mySQL?

推荐答案

您要使用语句的insert ... select形式:

INSERT INTO data_stocks (data_id,quantity)
    select ud.data_id, $quantity
    from users u join
         users_data ud
         on u.uid = ud.uid;

如果您仅针对一个用户执行此操作，则它看起来可能更像这样:

If you are doing this for only one user, it might look more like this:

INSERT INTO data_stocks (data_id,quantity)
    select ud.data_id, $quantity
    from users_data ud
    where ud.uid = $uid;

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