SQL查询以显示与另一个表的列中的条件完全匹配的数据

Question

到此时，我正在实现一个在3个表之间执行匹配的系统，并且现在我真的需要您的帮助，假设我有以下三个表：

表1：名称与项目之间的关系

User        Item
=====================
John Doe    Apple
John Doe    Orange
John Doe    Cat
John Doe    Dog
John Doe    Fish
Anna Sue    Apple
Anna Sue    Orange
Robinson    Banana
Robinson    Vessel
Robinson    Car

表2：对项目进行分类

Item Type   Item
==================
Fruit       Apple
Fruit       Orange
Fruit       Banana
Animal      Cat
Animal      Dog
Vehicle     Vessel
Vehicle     Car
Vehicle     Truck

表3：项目匹配

Match ID    Item Type
======================
M001        Fruit
M001        Animal
M002        Fruit
M002        Vehicle

我要问的是，我如何仅向所有用户显示所有条件都与指定匹配ID完全匹配的用户
在这种情况下，用户John Doe满足了在“ 水果和动物”中具有“ 比赛ID”中指定的关系且具有以下格式的所有条件的条件：

User            Match ID    Item Type   Item
================================================
John Doe        M001        Fruit       Apple
John Doe        M001        Fruit       Orange
John Doe        M001        Animal      Cat
John Doe        M001        Animal      Dog
Robinson        M002        Fruit       Banana
Robinson        M002        Vehicle     Vessel
Robinson        M002        Vehicle     Car

所有解决方案均受到高度赞赏，因此感谢您的帮助。

Answer 1

这是执行此操作的一种方法，但这将是对大型集合进行轻度调光的查询。

SQL Fiddle演示在这里： http ://sqlfiddle.com/#!2/63cd2/1

SELECT ui.user_name
     , tm.match_id
     , tm.item_type
     , ui.item
  FROM (SELECT uu.user_name
             , tm.match_id
             , COUNT(DISTINCT tm.item_type) AS cnt_item_type
          FROM (SELECT u.user_name FROM user_item u GROUP BY u.user_name) uu
         CROSS
          JOIN type_match tm
         GROUP BY uu.user_name, tm.match_id 
       ) n
  JOIN (SELECT hui.user_name
             , htm.match_id
             , COUNT(DISTINCT htm.item_type) AS cnt_item_type
          FROM user_item hui
          JOIN item_type hit ON hit.item = hui.item
          JOIN type_match htm ON htm.item_type = hit.item_type
         GROUP BY hui.user_name, htm.match_id
       ) h
    ON h.cnt_item_type = n.cnt_item_type
   AND h.match_id      = n.match_id
   AND h.user_name     = n.user_name
  JOIN user_item ui
    ON ui.user_name = h.user_name
  JOIN item_type it
    ON it.item = ui.item
  JOIN type_match tm
    ON tm.item_type = it.item_type
   AND tm.match_id = h.match_id
 ORDER
    BY ui.user_name
     , tm.match_id
     , tm.item_type
     , ui.item

别名为n的内联视图表示用户需要拥有的内容，以及满足每个match_id所需的所有item_type。

别名为h的内联视图表示用户实际拥有的内容，即用户对每个match_id拥有的所有item_type。

我们可以得到每个集合中不同item_type的计数，并进行比较。 如果计数相等，则我们知道用户具有该match_id的所有必需item_type。

最后，我们可以将其重新连接到用户实际拥有的商品，以便显示结果。

（同样，这将是可怕的调光器，尽管索引会有所帮助。）

Answer 2

尝试这个：

SELECT [User],  [Match ID], [Item Type],[Item]
From table1 
Inner join table2 on table1.item = table2.item
Inner join table3 on table2.[item type]= table3.[item type]
Where [User] = 'SOME USER NAME' AND table2.[item type] = 'SOME ITEM TYPE' AND table1.Item = 'SOME ITEM'

Answer 3

使用它，它的工作原理：

select t1.[User],t3.matchid,t3.item_type,t1.item from table3 t3 left join table2 t2 on t3.item_type=t2.Item_type left join table1 t1 on t2.Item=t1.Item    where t1.[user]='JohnDoe' and t3.MatchId='m001' group by t1.[user],t1.item,t3.MatchId,t3.Item_Type 

Answer 4

对于MySQL

小提琴

select t1.User,t3.MatchID,t3.ItemType as ItemType,t2.Item as Item 
from Table1 t1
inner join Table2 t2 on t1.Item = t2.Item
inner join Table3 t3 on t3.ItemType = t2.ItemType
inner join
(select user,MatchID
from 
(SELECT GROUP_CONCAT(ItemType ORDER BY ItemType) AS typesTomatch , MatchID
FROM Table3 GROUP BY MatchID) abc
inner join
(Select a.User, group_concat(distinct b.ItemType ORDER BY b.ItemType)
as typesofpeople
from Table1 As a
inner join Table2 As b on a.Item = b.Item
group by a.User order by b.ItemType) def
on abc.typesTomatch = def.TYPESOFPEOPLE) xyz
on xyz.User = t1.User and xyz.MatchID = t3.MatchID;

Answer 5

您在table3中有一个缺陷：1个数据（fruit）的2个ID（假设itemtype将是外键），否则查询将是：

select *
from table1 
   join table2 using (item)
   join table3 using (itemtype)

当然假设

1. itemtype是表2主键

2. itemtype是表3表2的外键

3. 项目是表1表2的外键