如何 select 记录所有加入的记录都不符合条件

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

我有一个具有以下 table 的设置(使用 MySQL):

我已经向 select orders 写了一个查询,其中 所有 他们的 products 属于某个 type

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 运行 类似几次:首先获取所有 FooProduct 的订单,然后再次获取所有 BarProduct 的订单。

我的症结在于生成第三个查询以获取所有其他订单,即他们所有产品的类型不完全是 FooProducts,或完全是 BarProducts(又名混合两者,或其他产品类型)。

所以,我的问题是如何获取 所有 产品类型不完全 FooProduct 或不完全 BarProduct 的所有记录。


这是一些示例数据,我想从中 return 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'

我试过这个,非常糟糕,所以作为潜台词放置,用以下内容代替现有的 AND(甚至语法也有偏差):

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')
)

您可以使用 Having 和基于条件聚合函数的过滤来代替相关子查询。

products.type IN ('FooProduct', 'BarProduct') 将 return 0 如果产品类型是其中的 none。我们可以在上面使用 Sum() 函数,进一步过滤。

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(*)

对于您要查找只有 FooProduct 类型的订单的情况,您可以使用以下代替:

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 

其实,这不太对。这会获取包含其他产品的订单,但不会获取仅包含 foo 和 bar 的订单。我认为这得到了其他人的支持:

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

这是一道关系除法题。
查找 所有产品都属于给定类型 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(*)
)

稍微调整上面的内容,找到所有产品都来自给定类型列表的订单是这样的:

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

要查找所有订单,其中所有产品都匹配给定列表中的所有类型,是这样的:

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

DB Fiddle with tests

这是一个基本的解决方案,效率不高但很简单:

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'