加入两个选择语句

Question

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有语法错误.

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SELECT一个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.

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

而且,使用另一个我希望得到的联接

Q_ID   P_ID1   Q1    P_ID2    Q2

1       180    3      181     11

2       180    9      181      6

3       180    5      181      3

也许我在这里采取了错误的做法.有什么建议？

更新:在RedFilter的指针之后,这对我有用:

(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

不确定你要做什么,但你有两个选择条款.改为:

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:

你可以把它减少到这样的东西:

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

Answer 2

如果要组合不同的结果集,则应使用UNION.请尝试以下方法:

(SELECT * 
 FROM ( SELECT * 
        FROM orders_products 
        INNER JOIN orders ON orders_products.orders_id = orders.orders_id  
        WHERE products_id = 181) AS A)
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)