具有多个条件的自连接

Question

我正在使用 mysql 来存储我的化学分析。并使用 html/php 过滤结果并生成查询以获取我想要的结果。现在事情对我来说变得复杂了，我正在尝试自己加入 table 以应用所有过滤器。

我的 table 设计是这样的，有超过 50k 行。

+--------+---------+-------------+----------------+
| Column |  Type   |    Index    |                |
+--------+---------+-------------+----------------+
| RID    | int     | primary_key | auto increment |
| ID     | int     | index       |                |
| Type   | int     |             |                |
| Order  | int     |             |                |
| Num    | int     |             |                |
| Val1   | decimal |             |                |
| Val2   | decimal |             |                |
+--------+---------+-------------+----------------+

每个样本都有一个 ID，不同的 types 和 order。 Val1 和 Val2 是 Num 类型分析的结果。现在有42个不同的Num。

例如，如果我的过滤器是这样的，

Select Types (1,3,9)
Select ANum (0,5)
Type 1, Num 5 should be bigger than 10 In Val2
Type 1, Num 5, should be smaller than 30 In Val2
Type 3, Num 0, should be smaller than 8 In Val1

我正在使用该查询生成结果。

SELECT analyse.* FROM analyse 
INNER JOIN 
(SELECT ID FROM analyse WHERE Type = 1 AND Num = 5 AND Val2 < 30) AS a1 ON a1.SID = analyse.SID 
INNER JOIN 
(SELECT SID FROM  WHERE Type = 1 AND Num = 5 AND Val2 > 10) AS a2 ON a2.SID = analyse.SID
INNER JOIN 
(SELECT SID FROM analyse WHERE Type = 3 AND Num = 0 AND Val1 > 8) AS a3 ON a2.SID = analyse.SID 
WHERE Type IN (1,3,9) AND Num IN (0,5) ORDER BY ID, Type, Order, Num ASC

+-----+------+-------+---------------+--------------+--------------+--------------+
| ID  | Type | Order | Val1[Num[0]]  | Val2[Num[0]] | Val1[Num[5]] | Val2[Num[5]] |
+-----+------+-------+---------------+--------------+--------------+--------------+
| ... | ...  | ...   | ...           | ...          | ...          | ...          |
| 118 | 1    | 1     | 10.9000       | 2.2083       | 3.5056       | 15.2627      |
| 118 | 1    | 2     | 9.5000        | 1.9246       | 2.0305       | 11.7049      |
| 118 | 1    | 3     | 7.9000        | 1.6005       | 2.4274       | 16.6597      |
| 118 | 2    | 1     | 10.9000       | 2.2083       | 3.5056       | 15.2627      |
| 118 | 3    | 2     | 20.4000       | 4.1329       | 2.8187       | 22.9676      |
| 118 | 4    | 3     | 28.3000       | 5.7334       | 2.7094       | 29.6273      |
| 119 | 1    | 1     | 27.2000       | 6.8635       | 0.5506       | 14.9084      |
| 119 | 1    | 2     | 25.9000       | 6.5355       | 0.4249       | 10.9550      |
| 119 | 3    | 1     | 27.2000       | 6.8635       | 0.5506       | 14.9084      |
| 119 | 3    | 2     | 53.1000       | 13.3989      | 0.4893       | 25.8634      |
| ... | ...  | ...   | ...           | ...          | ...          | ...          |
+-----+------+-------+---------------+--------------+--------------+--------------+

期望的输出应该是这样的。但是，由于还有其他 Val1 和 Val2 值具有相同的 ID、相同的类型但顺序不同，我猜 INNER JOIN 无法按预期工作。总是有比我的过滤器更大和更小的值出现。其中一些从未显示过。

抱歉，如果它太长了。我找不到正确的语句或结构。有什么建议吗？

编辑：抱歉。我忘了提及所有其他必须显示 ID 的数据。这就是我尝试使用 join 的原因。

Answer 1

因此，您对 table 的要求是

Select Types (1,3,9)
Select Num (0,5)
Type 1, Num 5 should be bigger than 10 In Val2
Type 1, Num 5, should be smaller than 30 In Val2
Type 3, Num 0, should be smaller than 8 In Val1

基本上有 4 个不同的标准需要评估（类型、数量、Val1、Val2）

虽然可能有 "better" 解决方案（在性能或更易于阅读的代码方面），但最简单的方法是创建不同的条件对，除非您处理数百万条记录，否则应该没问题。

根据您的要求，我认为您需要获取以下行集：

1.) Type = 1, Num = 5, Val2 > 10
2.) Type = 1, Num = 5, Val2 < 30
3.) Type = 3, Num = 0, Val1 < 8
4.) Type = 9

因此，这将是“4 个显式”查询的联合：

SELECT * FROM analyse WHERE Type = 1 AND Num = 5 AND Val2 > 10
UNION
SELECT * FROM analyse WHERE Type = 1 AND Num = 5 AND Val2 < 10
UNION
SELECT * FROM analyse WHERE Type = 3 AND Num = 0 AND Val1 < 8
UNION
SELECT * FROM analyse WHERE Type = 9

要通过 id 过滤最终结果，您可以简单地使用：

SELECT * FROM (
  SELECT * FROM analyse WHERE Type = 1 AND Num = 5 AND Val2 > 10
  UNION
  SELECT * FROM analyse WHERE Type = 1 AND Num = 5 AND Val2 < 10
  UNION
  SELECT * FROM analyse WHERE Type = 3 AND Num = 0 AND Val1 < 8
  UNION
  SELECT * FROM analyse WHERE Type = 9
) as tempTable WHERE id = 118

或者只是将 id 附加到每个独立的查询。

Answer 2

我已经通过同时查询相同的 Nums 和 Types 而不是使用单独的连接获取它们来解决了我的问题。这样，其他相同 Num 和 Type 的数据将无法通过过滤器。

对于那个条件

Select Types (1,3,9)
Select ANum (0,5)
Type 1, Num 5 should be bigger than 10 In Val2
Type 1, Num 5, should be smaller than 30 In Val2
Type 3, Num 0, should be smaller than 8 In Val1

查询应该是这样的，

SELECT analyse.* FROM analyse 
INNER JOIN 
(SELECT ID FROM analyse WHERE Type = 1 AND Num = 5 AND Val2 < 30 AND Val2 > 10) AS a1 ON a1.SID = analyse.SID 
(SELECT SID FROM analyse WHERE Type = 3 AND Num = 0 AND Val1 > 8) AS a3 ON a2.SID = analyse.SID 
WHERE Type IN (1,3,9) AND Num IN (0,5) ORDER BY ID, Type, Order, Num ASC

具有多个条件的自连接

Self Join With Multiple Conditions

mysql

join

inner-join

self-join