mysql - 加入两个选择语句

Question

谁能告诉我为什么以下不起作用？它提示两个选择之间的连接关键字附近的语法错误。

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

基本上我的第一个 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。

现在，我有

_______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

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?

UPDATE:Here is what worked for me after pointers by RedFilter:

(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
) 

Answer 1

不确定您要做什么，但您有两个选择子句。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

更新:

你可能会把它简化成这样:

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