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如何选择所有联接记录都不符合条件的记录

[英]How to select records where all joined records aren't a match for criteria

我使用以下表格进行了设置(使用MySQL):

  • orders ,其中有很多:
  • order_itemsorder_items ,其中一个来自:
  • products

我写了一个查询来选择所有 products均为某种type orders

SELECT orders.* FROM orders 
INNER JOIN order_items ON order_items.order_id = orders.id   
INNER JOIN products ON products.id = order_items.product_id     
WHERE products.type = 'FooProduct'
AND (
  NOT EXISTS (
    SELECT null
    FROM products
    INNER JOIN order_items ON order_items.product_id = products.id
    WHERE order_items.order_id = orders.id
    AND products.type != 'FooProduct'
  )
 )

我也进行了两次类似的操作:首先要获取包含所有FooProduct的订单,然后再次获取所有BarProduct的订单。

我的症结一直是生成第三个查询以获取所有其他订单,即,其所有产品的类型都不都是FooProductBarProduct (又是两种或其他产品类型的混合)。

所以,我的问题是如何获得的所有记录, 所有的产品类型是不完全FooProduct S或专门BarProduct


以下是一些示例数据,我想从中返回ID为3和4的订单:

- orders
id
 1
 2
 3
 4

-- order_items

id order_id product_id
 1        1          1
 2        1          1
 3        2          2
 4        2          2
 5        3          3
 6        3          4
 7        4          1
 8        4          2

-- products
id type
 1 'FooProduct'
 2 'BarProduct'
 3 'OtherProduct'
 4 'YetAnotherProduct'

我已经尝试过了,因此非常遗憾地将其放置为子文本,并用以下内容代替了现有的AND (即使语法很不正确):

NOT HAVING COUNT(order_items.*) = (
  SELECT null
        FROM products
        INNER JOIN order_items ON  order_items.product_id = products.id
        WHERE order_items.order_id = orders.id
        AND products.type IN ('FooProduct', 'BarProduct')
)

而不是使用相关子查询的,可以使用Having和条件聚合函数基于内容的过滤。

如果产品类型都不是,那么products.type IN ('FooProduct', 'BarProduct')将返回0。 我们可以在其上使用Sum()函数进行进一步的过滤。

请尝试以下操作:

SELECT orders.order_id 
FROM orders 
INNER JOIN order_items ON order_items.order_id = orders.id   
INNER JOIN products ON products.id = order_items.product_id 
GROUP BY orders.order_id 
HAVING SUM(products.type IN ('FooProduct', 'BarProduct')) < COUNT(*)

对于这种情况,如果要查找仅具有FooProduct类型的订单,则可以改用以下内容:

SELECT orders.order_id 
FROM orders 
INNER JOIN order_items ON order_items.order_id = orders.id   
INNER JOIN products ON products.id = order_items.product_id 
GROUP BY orders.order_id 
HAVING SUM(products.type <> 'FooProduct') = 0

另一种可能的方法是:

SELECT orders.order_id 
FROM orders 
INNER JOIN order_items ON order_items.order_id = orders.id   
INNER JOIN products ON products.id = order_items.product_id 
GROUP BY orders.order_id 
HAVING SUM(products.type = 'FooProduct') = COUNT(*)

您可以为此使用聚合和having子句:

SELECT o.*
FROM orders o INNER JOIN
     order_items oi
     ON oi.order_id = o.id INNER JOIN
     products p
     ON p.id = oi.product_id   
GROUP BY o.id  -- OK assuming `id` is the primary key
HAVING SUM(p.type NOT IN ('FooProduct', 'BarProduct')) > 0;  -- at least one other product 

实际上,那是不正确的。 这会获得具有其他产品的订单,但不会选择仅由foo和bar混合而成的订单。 我认为这会吸引其他人:

HAVING SUM(p.type = 'FooProduct') < COUNT(*) AND
       SUM(p.type = 'BarProduct') < COUNT(*) 

这是一个关系划分问题。
查找所有给定类型产品的订单的一种解决方案是:

SELECT *
FROM orders
INNER JOIN order_items ON order_items.order_id = orders.id
INNER JOIN products ON products.id = order_items.product_id
WHERE orders.id IN (
    SELECT order_items.order_id
    FROM order_items
    INNER JOIN products ON products.id = order_items.product_id
    GROUP BY order_items.order_id
    HAVING COUNT(CASE WHEN products.type = 'FooProduct' THEN 1 END) = COUNT(*)
)

稍微调整一下上面的内容,即可从给定类型的列表中找到所有产品都来自的订单:

HAVING COUNT(CASE WHEN products.type IN ('FooProduct', 'BarProduct') THEN 1 END) = COUNT(*)

从给定列表中查找所有产品与所有类型匹配的所有订单的方法是:

HAVING COUNT(CASE WHEN products.type IN ('FooProduct', 'BarProduct') THEN 1 END) = COUNT(*)
AND    COUNT(DISTINCT products.type) = 2

DB Fiddle测试

这是一个基本解决方案,效率不高,但很容易:

SELECT * FROM orders WHERE id NOT IN (
    SELECT orders.id FROM orders 
    INNER JOIN order_items ON order_items.order_id = orders.id   
    INNER JOIN products ON products.id = order_items.product_id     
    WHERE products.type = 'FooProduct'
    AND (
      NOT EXISTS (
        SELECT null
        FROM products
        INNER JOIN order_items ON order_items.product_id = products.id
        WHERE order_items.order_id = orders.id
        AND products.type != 'FooProduct'
      )
 )
) AND id NOT IN (
    SELECT orders.id FROM orders 
    INNER JOIN order_items ON order_items.order_id = orders.id   
    INNER JOIN products ON products.id = order_items.product_id     
    WHERE products.type = 'BarProduct'
    AND (
      NOT EXISTS (
        SELECT null
        FROM products
        INNER JOIN order_items ON order_items.product_id = products.id
        WHERE order_items.order_id = orders.id
        AND products.type != 'BarProduct'
      )
 )
)

我建议像这样在连接的子选择中使用count(distinct):

SELECT orders.*
FROM orders 
inner join (
    SELECT orderid, max(products.type) as products_type
    FROM order_items
    INNER JOIN products ON products.id = order_items.product_id
    GROUP BY orderid
    -- distinct count of different products = 1 
    --    -> all order items are for the same product type
    HAVING COUNT(distinct products.type ) = 1 
    -- alternative is:
    -- min(products.type )=max(products.type )
) as tmp on tmp.orderid=orders.orderid 
WHERE 1=1
-- if you want only single type product orders for some specific product
and tmp.products_type = 'FooProduct'

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