MySQL 加入两个选择语句
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joining two select statements
提问by Codrguy
Can anyone tell me why the following won't work? It complains of a syntax error near the join key word between the two selects.
谁能告诉我为什么以下不起作用？它抱怨两个选择之间的连接关键字附近存在语法错误。
SELECT *
FROM ( select * from orders_products inner JOIN orders ON orders_products.orders_id = orders.orders_id where products_id = 181)
as A
join
SELECT *
FROM ( select * from orders_products INNER JOIN orders ON orders_products.orders_id = orders.orders_id where products_id = 180)
as B
on A.orders_id=B.orders_id
Basically my first SELECTpulls all the order info for a certain product from one table and pulls the quantity ordered from another and joins them together. The second SELECTdoes the same thing for another product.
基本上，我首先SELECT从一个表中提取某个产品的所有订单信息，然后从另一个表中提取订购的数量并将它们连接在一起。第二个SELECT对另一个产品做同样的事情。
Now, I have
我现在有
_______A_________ _______B_________
O_ID P_ID Q O_ID P_ID Q
1 180 3 1 181 11
2 180 9 2 181 6
3 180 5 3 181 3
And, using another join I want to get
并且，使用我想要的另一个连接
Q_ID P_ID1 Q1 P_ID2 Q2
1 180 3 181 11
2 180 9 181 6
3 180 5 181 3
Maybe I am taking a wrong approach here. Any suggestions?
也许我在这里采取了错误的方法。有什么建议？
UPDATE: Here is what worked for me after pointers by RedFilter:
更新：以下是 RedFilter 指示后对我有用的方法：
(SELECT *
FROM (
SELECT * FROM orders_products
INNER JOIN orders ON orders_products.orders_id = orders.orders_id
WHERE products_id =181) AS A
LEFT JOIN (
SELECT * FROM orders_products
INNER JOIN orders ON orders_products.orders_id = orders.orders_id
WHERE products_id =180) AS B ON A.orders_id = B.orders_id
)
UNION (
SELECT *
FROM (
SELECT *
FROM orders_products
INNER JOIN orders ON orders_products.orders_id = orders.orders_id
WHERE products_id =181
) AS C
RIGHT JOIN (
SELECT *
FROM orders_products
INNER JOIN orders ON orders_products.orders_id = orders.orders_id
WHERE products_id =180
) AS D ON C.orders_id = D.orders_id
)
回答by RedFilter
Not sure what you are trying to do, but you have two select clauses. Do this instead:
不确定您要做什么，但是您有两个 select 子句。改为这样做：
SELECT *
FROM ( SELECT *
FROM orders_products
INNER JOIN orders ON orders_products.orders_id = orders.orders_id
WHERE products_id = 181) AS A
JOIN ( SELECT *
FROM orders_products
INNER JOIN orders ON orders_products.orders_id = orders.orders_id
WHERE products_id = 180) AS B
ON A.orders_id=B.orders_id
Update:
更新：
You could probably reduce it to something like this:
您可能可以将其简化为这样的：
SELECT o.orders_id,
op1.products_id,
op1.quantity,
op2.products_id,
op2.quantity
FROM orders o
INNER JOIN orders_products op1 on o.orders_id = op1.orders_id
INNER JOIN orders_products op2 on o.orders_id = op2.orders_id
WHERE op1.products_id = 180
AND op2.products_id = 181
回答by alexn
You should use UNIONif you want to combine different resultsets. Try the following:
如果您想组合不同的结果集，您应该使用UNION。请尝试以下操作：
(SELECT *
FROM ( SELECT *
FROM orders_products
INNER JOIN orders ON orders_products.orders_id = orders.orders_id
WHERE products_id = 181) AS A)
UNION
(SELECT *
FROM ( SELECT *
FROM orders_products
INNER JOIN orders ON orders_products.orders_id = orders.orders_id
WHERE products_id = 180) AS B
ON A.orders_id=B.orders_id)
回答by maple_shaft
This will do what you want:
这将执行您想要的操作：
select *
from orders_products
INNER JOIN orders
ON orders_products.orders_id = orders.orders_id
where products_id in (180, 181);
回答by Narendra Kumar Achari
SELECT *
FROM
(First_query) AS ONE
LEFT OUTER JOIN
(Second_query ) AS TWO ON ONE.First_query_ID = TWO.Second_Query_ID;
