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

而且，使用另一个加入我想得到 ​​p>

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方法。有什么建议吗？

更新： 在 RedFilter 的指示之后，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：

你可以把它简化成这样：

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

Answer 2

如果你想组合不同的结果集，你应该使用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)

Answer 3

这会做你想做的事：

select * 
  from orders_products 
       INNER JOIN orders 
          ON orders_products.orders_id = orders.orders_id
 where products_id in (180, 181);

Answer 4

SELECT *
FROM
  (First_query) AS ONE
LEFT OUTER JOIN
  (Second_query ) AS TWO ON ONE.First_query_ID = TWO.Second_Query_ID;