Php 管理数量未知的EAV属性上的联接_Php_Mysql

Php 管理数量未知的EAV属性上的联接

php mysql

Php 管理数量未知的EAV属性上的联接,php,mysql,Php,Mysql,给定一个名为item的表，其中包含“主”记录，例如： item_id item_type item_name item_description 1 clothing T-Shirt Get your t-shirt here 2 clothing Polo Shirt Another kind of short-sleeve shirt 3 computer Macbook 2

给定一个名为

item

的表，其中包含“主”记录，例如：

item_id    item_type    item_name    item_description
1          clothing     T-Shirt      Get your t-shirt here
2          clothing     Polo Shirt   Another kind of short-sleeve shirt
3          computer     Macbook      2016 Macbook Pro with retina

$attributes = ['size', 'color'];

还有另一个名为

custom_fields

的表，我认为它具有EAV结构（实体属性值）：

对包含所有指定/配置属性的查询进行编码的最佳方法是什么，这些属性也将支持排序依据

事实：
1.数据结构无法更改。
2.属性未知（用户配置）。 3.在技术上，可以为给定类型的项目设置无限数量的“属性”（如上面的

大小

或

颜色

）（实际上，我无法想象超过50个）。
4.查询中包括/不包括哪些属性未知（用户配置）

假设指定的属性存在于数组中，例如：

item_id    item_type    item_name    item_description
1          clothing     T-Shirt      Get your t-shirt here
2          clothing     Polo Shirt   Another kind of short-sleeve shirt
3          computer     Macbook      2016 Macbook Pro with retina

$attributes = ['size', 'color'];

似乎有些PHP的功能如下：

$counter = 1;
$from = 'item AS i';
$fields = 'name, description';
$order_by = 'size';

foreach( $attributes AS $attribute ) {
    $table_alias = "a{$counter}";
    $fields.= ",{$table_alias}.value AS {$attribute}";
    $from.= " INNER JOIN custom_fields AS {$table_alias} ON i.item_id = {$table_alias}.item_id AND {$table_alias}.attribute = '{$attribute}'";
    $counter++;
}   

$query = "SELECT {$fields} FROM {$from} {$where} ORDER BY {$order_by}";

SELECT name, description, a1.value AS size, a2.value AS color 
    FROM item AS i 
    INNER JOIN custom_fields AS a1 ON i.item_id = a1.item_id 
        AND a1.attribute = 'size'
    INNER JOIN custom_fields AS a2 ON i.item_id = a2.item_id 
        AND a2.attribute = 'color'

将构造一个查询，该查询既可用于包含数据，也可用于允许ORDER BY。该查询类似于：

$counter = 1;
$from = 'item AS i';
$fields = 'name, description';
$order_by = 'size';

foreach( $attributes AS $attribute ) {
    $table_alias = "a{$counter}";
    $fields.= ",{$table_alias}.value AS {$attribute}";
    $from.= " INNER JOIN custom_fields AS {$table_alias} ON i.item_id = {$table_alias}.item_id AND {$table_alias}.attribute = '{$attribute}'";
    $counter++;
}   

$query = "SELECT {$fields} FROM {$from} {$where} ORDER BY {$order_by}";

SELECT name, description, a1.value AS size, a2.value AS color 
    FROM item AS i 
    INNER JOIN custom_fields AS a1 ON i.item_id = a1.item_id 
        AND a1.attribute = 'size'
    INNER JOIN custom_fields AS a2 ON i.item_id = a2.item_id 
        AND a2.attribute = 'color'

但是，如果有20多个列，我担心的是这个查询看起来很讨厌（20个

连接），可能会有性能问题
有没有更好的方法来组织这个？是否有一些方法（例如使用临时表）更有用或性能更好
更新：

MySQL的版本无法确保是任何特定的，因此这应该与任何版本兼容，因此请假设版本5.0
您也可以只使用一个**连接*来完成此操作，如下所示：
SELECT m.*
    ,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
    ,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
    ,GROUP_CONCAT(IF(cf.attribute = 'memory', cf.`value`, NULL)) AS 'memory'
    ,GROUP_CONCAT(IF(cf.attribute = 'hard drive', cf.`value`, NULL)) AS 'hard drive'
FROM master m
LEFT JOIN custom_fields cf ON m.item_id = cf.item_id
GROUP BY m.item_id;

要生成产品（或更多）的查询，您可以使用：
对于所有产品，删除（1）中项目id所在的行
选择m*
select DISTINCT
 CONCAT("SELECT m.*\n"
 , GROUP_CONCAT(",GROUP_CONCAT(IF(cf.attribute = '",attribute,"', cf.`value`, NULL)) AS '",attribute,"'" SEPARATOR '\n')
 , "FROM master m\nLEFT JOIN custom_fields cf ON m.item_id = cf.item_id\nGROUP BY m.item_id") as myquery
FROM custom_fields
WHERE item_id in (1);

样本
mysql> select DISTINCT
    ->  CONCAT("SELECT m.*\n"
    ->  , GROUP_CONCAT(",GROUP_CONCAT(IF(cf.attribute = '",attribute,"', cf.`value`, NULL)) AS '",attribute,"'" SEPARATOR '\n')
    ->  , "FROM master m\nLEFT JOIN custom_fields cf ON m.item_id = cf.item_id\nGROUP BY m.item_id") as myquery
    -> FROM custom_fields;

结果
    SELECT m.*
,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
,GROUP_CONCAT(IF(cf.attribute = 'memory', cf.`value`, NULL)) AS 'memory'
,GROUP_CONCAT(IF(cf.attribute = 'hard drive', cf.`value`, NULL)) AS 'hard drive'FROM master m
LEFT JOIN custom_fields cf ON m.item_id = cf.item_id
GROUP BY m.item_id 

1 row in set (0,00 sec)

mysql>

并执行此查询
mysql>  SELECT m.*
    -> ,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'memory', cf.`value`, NULL)) AS 'memory'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'hard drive', cf.`value`, NULL)) AS 'hard drive'FROM master m
    -> LEFT JOIN custom_fields cf ON m.item_id = cf.item_id
    -> GROUP BY m.item_id ;
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
| item_id | item_type | item_name  | item_description                   | size   | color  | size   | color  | memory | hard drive |
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
|       1 | clothing  | T-Shirt    | Get your t-shirt here              | large  | purple | large  | purple | NULL   | NULL       |
|       2 | clothing  | Polo Shirt | Another kind of short-sleeve shirt | medium | green  | medium | green  | NULL   | NULL       |
|       3 | computer  | macbook    | 2016 Macbook Pro with retina       | NULL   | NULL   | NULL   | NULL   | 16GB   | 512GB SSD  |
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
3 rows in set (0,00 sec)

mysql>

准备好陈述的样本
mysql> select DISTINCT
    ->  CONCAT("SELECT m.*\n"
    ->  , GROUP_CONCAT(",GROUP_CONCAT(IF(cf.attribute = '",attribute,"', cf.`value`, NULL)) AS '",attribute,"'" SEPARATOR '\n')
    ->  , "FROM master m\nLEFT JOIN custom_fields cf ON m.item_id = cf.item_id\nGROUP BY m.item_id") as myquery INTO @sql
    -> FROM custom_fields;
Query OK, 1 row affected (0,00 sec)

mysql> PREPARE stmt FROM @sql;
Query OK, 0 rows affected (0,01 sec)
Statement prepared

mysql> execute stmt;
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
| item_id | item_type | item_name  | item_description                   | size   | color  | size   | color  | memory | hard drive |
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
|       1 | clothing  | T-Shirt    | Get your t-shirt here              | large  | purple | large  | purple | NULL   | NULL       |
|       2 | clothing  | Polo Shirt | Another kind of short-sleeve shirt | medium | green  | medium | green  | NULL   | NULL       |
|       3 | computer  | macbook    | 2016 Macbook Pro with retina       | NULL   | NULL   | NULL   | NULL   | 16GB   | 512GB SSD  |
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
3 rows in set (0,00 sec)

mysql> DEALLOCATE PREPARE stmt;
Query OK, 0 rows affected (0,00 sec)

mysql>

您也可以只使用一个**连接*来完成此操作，如下所示：
SELECT m.*
    ,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
    ,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
    ,GROUP_CONCAT(IF(cf.attribute = 'memory', cf.`value`, NULL)) AS 'memory'
    ,GROUP_CONCAT(IF(cf.attribute = 'hard drive', cf.`value`, NULL)) AS 'hard drive'
FROM master m
LEFT JOIN custom_fields cf ON m.item_id = cf.item_id
GROUP BY m.item_id;

要生成产品（或更多）的查询，您可以使用：
对于所有产品，删除（1）中项目id所在的行
选择m*
select DISTINCT
 CONCAT("SELECT m.*\n"
 , GROUP_CONCAT(",GROUP_CONCAT(IF(cf.attribute = '",attribute,"', cf.`value`, NULL)) AS '",attribute,"'" SEPARATOR '\n')
 , "FROM master m\nLEFT JOIN custom_fields cf ON m.item_id = cf.item_id\nGROUP BY m.item_id") as myquery
FROM custom_fields
WHERE item_id in (1);

样本
mysql> select DISTINCT
    ->  CONCAT("SELECT m.*\n"
    ->  , GROUP_CONCAT(",GROUP_CONCAT(IF(cf.attribute = '",attribute,"', cf.`value`, NULL)) AS '",attribute,"'" SEPARATOR '\n')
    ->  , "FROM master m\nLEFT JOIN custom_fields cf ON m.item_id = cf.item_id\nGROUP BY m.item_id") as myquery
    -> FROM custom_fields;

结果
    SELECT m.*
,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
,GROUP_CONCAT(IF(cf.attribute = 'memory', cf.`value`, NULL)) AS 'memory'
,GROUP_CONCAT(IF(cf.attribute = 'hard drive', cf.`value`, NULL)) AS 'hard drive'FROM master m
LEFT JOIN custom_fields cf ON m.item_id = cf.item_id
GROUP BY m.item_id 

1 row in set (0,00 sec)

mysql>

并执行此查询
mysql>  SELECT m.*
    -> ,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'size', cf.`value`, NULL)) AS 'size'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'color', cf.`value`, NULL)) AS 'color'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'memory', cf.`value`, NULL)) AS 'memory'
    -> ,GROUP_CONCAT(IF(cf.attribute = 'hard drive', cf.`value`, NULL)) AS 'hard drive'FROM master m
    -> LEFT JOIN custom_fields cf ON m.item_id = cf.item_id
    -> GROUP BY m.item_id ;
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
| item_id | item_type | item_name  | item_description                   | size   | color  | size   | color  | memory | hard drive |
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
|       1 | clothing  | T-Shirt    | Get your t-shirt here              | large  | purple | large  | purple | NULL   | NULL       |
|       2 | clothing  | Polo Shirt | Another kind of short-sleeve shirt | medium | green  | medium | green  | NULL   | NULL       |
|       3 | computer  | macbook    | 2016 Macbook Pro with retina       | NULL   | NULL   | NULL   | NULL   | 16GB   | 512GB SSD  |
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
3 rows in set (0,00 sec)

mysql>

准备好陈述的样本
mysql> select DISTINCT
    ->  CONCAT("SELECT m.*\n"
    ->  , GROUP_CONCAT(",GROUP_CONCAT(IF(cf.attribute = '",attribute,"', cf.`value`, NULL)) AS '",attribute,"'" SEPARATOR '\n')
    ->  , "FROM master m\nLEFT JOIN custom_fields cf ON m.item_id = cf.item_id\nGROUP BY m.item_id") as myquery INTO @sql
    -> FROM custom_fields;
Query OK, 1 row affected (0,00 sec)

mysql> PREPARE stmt FROM @sql;
Query OK, 0 rows affected (0,01 sec)
Statement prepared

mysql> execute stmt;
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
| item_id | item_type | item_name  | item_description                   | size   | color  | size   | color  | memory | hard drive |
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
|       1 | clothing  | T-Shirt    | Get your t-shirt here              | large  | purple | large  | purple | NULL   | NULL       |
|       2 | clothing  | Polo Shirt | Another kind of short-sleeve shirt | medium | green  | medium | green  | NULL   | NULL       |
|       3 | computer  | macbook    | 2016 Macbook Pro with retina       | NULL   | NULL   | NULL   | NULL   | 16GB   | 512GB SSD  |
+---------+-----------+------------+------------------------------------+--------+--------+--------+--------+--------+------------+
3 rows in set (0,00 sec)

mysql> DEALLOCATE PREPARE stmt;
Query OK, 0 rows affected (0,00 sec)

mysql>

使用MySQL 5.7，可以考虑将属性检索为JSON:
SELECT 
    i.item_id,
    i.item_name,
    i.item_description,
    CONCAT('{',
            GROUP_CONCAT(CONCAT(JSON_QUOTE(a1.attribute),
                        ':',
                        JSON_QUOTE(a1.value))
                SEPARATOR ','),
            '}') AS att
FROM
    item AS i
        INNER JOIN
    custom_fields AS a1 ON i.item_id = a1.item_id
        INNER JOIN
    custom_fields AS a2 ON i.item_id = a2.item_id
        AND a2.attribute = 'size'

WHERE
    a1.attribute IN ('color' , 'size')
GROUP BY 1
ORDER BY a2.value DESC

结果:
+---------+------------+------------------------------------+-----------------------------------+
| item_id | item_name  | item_description                   | att                               |
+---------+------------+------------------------------------+-----------------------------------+
|       2 | Polo Shirt | Another kind of short-sleeve shirt | {"size":"medium","color":"green"} |
|       1 | T-Shirt    | Get your t-shirt here              | {"size":"large","color":"purple"} |
+---------+------------+------------------------------------+-----------------------------------+

假设自定义\u字段具有唯一索引（项\u id，属性）
和a2.attribute='size'
是动态部分，您可以在其中定义要排序的属性，也可以在其中定义要提取的属性
它的行为与原始多连接查询略有不同。如果缺少一个或多个属性，它仍然返回该项。
< P>使用MySQL 5.7，可以考虑将属性检索为JSON:
SELECT 
    i.item_id,
    i.item_name,
    i.item_description,
    CONCAT('{',
            GROUP_CONCAT(CONCAT(JSON_QUOTE(a1.attribute),
                        ':',
                        JSON_QUOTE(a1.value))
                SEPARATOR ','),
            '}') AS att
FROM
    item AS i
        INNER JOIN
    custom_fields AS a1 ON i.item_id = a1.item_id
        INNER JOIN
    custom_fields AS a2 ON i.item_id = a2.item_id
        AND a2.attribute = 'size'

WHERE
    a1.attribute IN ('color' , 'size')
GROUP BY 1
ORDER BY a2.value DESC

结果:
+---------+------------+------------------------------------+-----------------------------------+
| item_id | item_name  | item_description                   | att                               |
+---------+------------+------------------------------------+-----------------------------------+
|       2 | Polo Shirt | Another kind of short-sleeve shirt | {"size":"medium","color":"green"} |
|       1 | T-Shirt    | Get your t-shirt here              | {"size":"large","color":"purple"} |
+---------+------------+------------------------------------+-----------------------------------+

假设自定义\u字段具有唯一索引（项\u id，属性）
和a2.attribute='size'
是动态部分，您可以在其中定义要排序的属性，也可以在其中定义要提取的属性
它的行为与原始多连接查询略有不同。如果缺少一个或多个属性，它仍然返回该项。
有趣的方法。我正在跟踪它是如何工作的/它是做什么的。@cale_b-您也可以直接将第二条语句作为准备语句执行。我将在几分钟后用有趣的方法在我的答案末尾添加一个示例。我正在跟踪它是如何工作的/它是做什么的。@cale_b-您也可以直接将第二条语句作为准备语句执行。几分钟后，我会在我的答案末尾加上一个例子。使用这种方法，我将如何按照“颜色”进行排序？只是用一些解释更新了答案。要按颜色排序，您需要使用和a2.attribute='color'
我刚刚实现了一个分布式软件包，我无法可靠地依赖mysql 5.7+的安装。糟糕，因为这是一个很酷的想法。好吧，对于mysql来说，这是一个有趣的想法。使用这种方法，我将如何按照“颜色”进行排序？只是用一些解释更新了答案。要按颜色排序，您需要使用和a2.attribute='color'
我刚刚实现了一个分布式软件包，我无法可靠地依赖mysql 5.7+的安装。糟糕，因为这是一个很酷的主意。好吧，对于mysql来说