php - 从包含不同和不相关信息的多个表中获取 mysql 搜索结果

Question

我一直在与客户合作，并不断回到这个查询问题，试图找到解决方案，我一直在谷歌搜索，但没有找到相关结果。

我的客户有多种旅行服务，例如邮轮、海滩度假村、酒店、小木屋等。

我已经更新了所有单独的搜索页面，并一直致力于让组合搜索页面发挥作用。

旅行服务的表完全不相关，并且不共享很多字段名称。

在组合搜索页面上，我试图根据用户搜索词从多个表中获取搜索结果。因此，如果用户输入“夏威夷”作为搜索词，他们应该会看到以夏威夷为停靠港的游轮、夏威夷酒店、夏威夷海滩度假村等的结果。

例如这里有3个表(简化了，现场还有很多其他字段):

餐 table 美食:

+----+--------------+-------------+-------+------+
| id | cruise_name  | destination | price | deck |
+----+--------------+-------------+-------+------+
|  1 | royal cruise | Hawaii      | 1000  | 1    |
|  2 | crown cruise | St. Martin  | 1200  | 2    |
+----+--------------+-------------+-------+------+

餐 table 酒店:

+----+--------------+-------------+-------+------+
| id | hotel_name   | location    | price | beds |
+----+--------------+-------------+-------+------+
|  1 | sheraton     | Hawaii      | 139   | 2    |
|  2 | meriott      | Florida     | 75    | 2    |
+----+--------------+-------------+-------+------+

餐 table 度假村:

+----+--------------+-------------+-------+-----------+
| id | resort       | location    | price | room_type |
+----+--------------+-------------+-------+-----------+
|  1 | sandals      | Jamaica     | 2000  | 3         |
|  2 | dream resort | Hawaii      | 2300  | 1         |
+----+--------------+-------------+-------+-----------+

举个简单的例子，假设我有一个用户搜索“夏威夷”，我需要向他们显示上述每个表格的结果。

我得到的最接近的查询是这样的:

SELECT  
    cuises.id AS cruise_id, 
    cuises.cruise_name AS cruise_cruise_name, 
    cuises.destination AS cruise_destination, 
    cuises.price AS cruise_price, 
    cuises.deck AS cruise_deck, 

    hotels.id AS hotels_id, 
    hotels.hotel_name AS hotels_hotel_name, 
    hotels.location AS hotels_location, 
    hotels.price AS hotels_price,
    hotels.beds AS hotels_beds,

    resorts.id AS resorts_id, 
    resorts.resort AS resorts_resort, 
    resorts.location AS resorts_location, 
    resorts.price AS resorts_price,
    resorts.room_type AS resorts_room_type

FROM 
    cuises,
    hotels,
    vacation_packages,
    resorts 

WHERE 
    (cuises.cruise_name LIKE '%Hawaii%') OR
    (hotels.hotel_name LIKE '%Hawaii%') OR
    (resorts.resort LIKE '%Hawaii%')                      

上述样式查询将结果混合到包含来自多个表的数据的行中，而我正在寻找的是每行仅包含一个表格中的信息的行。

我希望 psuedo-tabel 从查询中看起来像这样，这样我就可以轻松地在 PHP 中解析结果:

+-----------+---------------------+--------------------+--------------+-------------+-----------+---------------------+--------------------+--------------+-------------+------------+----------------------+---------------------+---------------+-------------------+
| cruise_id | cruise_cruise_name  | cruise_destination | cruise_price | cruise_deck | hotels_id | hotels_hotel_name   | hotels_location    | hotels_price | hotels_beds | resorts_id | resorts_resort       | resorts_location    | resorts_price | resorts_room_type |
+-----------+---------------------+--------------------+--------------+-------------+-----------+---------------------+--------------------+--------------+-------------+------------+----------------------+---------------------+---------------+-------------------+
|  1        | royal cruise        | Hawaii             | 1000         | 1           |           |                     |                    |              |             |            |                      |                     |               |                   |
|  2        | crown cruise        | St. Martin         | 1200         | 2           |           |                     |                    |              |             |            |                      |                     |               |                   |
|           |                     |                    |              |             |  1        | sheraton            | Hawaii             | 139          | 2           |            |                      |                     |               |                   |
|           |                     |                    |              |             |  2        | meriott             | Florida            | 75           | 2           |            |                      |                     |               |                   |
|           |                     |                    |              |             |           |                     |                    |              |             |  1         | sandals              | Jamaica             | 2000          | 3                 |
|           |                     |                    |              |             |           |                     |                    |              |             |  2         | dream resort         | Hawaii              | 2300          | 1                 |
+-----------+---------------------+--------------------+--------------+-------------+-----------+---------------------+--------------------+--------------+-------------+------------+----------------------+---------------------+---------------+-------------------+

基本上，如果我可以跨多个表合并我的搜索结果，其中它们的字段像上表一样放在一起，并且度假村的字段在具有酒店信息等的行中为空。然后我可以轻松使用 LIMIT 和 OFFSET 对返回的数据进行分页，并使用 PHP 将返回的信息作为数组循环，并根据不为空的 id 字段确定行中的旅行服务以显示该行的信息使用正确的模板。

有没有一种方法可以查询多个表格，并将它们的行合并到一个不会混淆数据的结果集中？

Answer 1

你想要一个 union query ，这将对您的每个表进行单独选择，并将所有结果连接到一个查询中。联合查询的规定是所有联合查询必须返回相同数量的列，因此您需要从每个子查询的所有其他表中select null as fieldname:

SELECT * FROM (
    (SELECT  
        cuises.id AS cruise_id, 
        cuises.cruise_name AS cruise_cruise_name, 
        cuises.destination AS cruise_destination, 
        cuises.price AS cruise_price, 
        cuises.deck AS cruise_deck,
        null as hotels_id, null as hotels_hotel_name, null as hotels_location, null as hotels_price, null as hotels_beds,
        null as resorts_id, null as resorts_resort, null as resorts_location, null as resorts_price, null as resorts_room_type
    FROM cruises
    WHERE cruises.cruise_name LIKE '%Hawaii%')

    UNION ALL

    (SELECT
        null as cruise_id, null as cruise_cruise_name, null as cruise_destination, null as cruise_price, null as cruise_deck,
        hotels.id AS hotels_id, 
        hotels.hotel_name AS hotels_hotel_name, 
        hotels.location AS hotels_location, 
        hotels.price AS hotels_price,
        hotels.beds AS hotels_beds
        null as resorts_id, null as resorts_resort, null as resorts_location, null as resorts_price, null as resorts_room_type
    FROM hotels
    WHERE hotels.hotel_name LIKE '%Hawaii%')

    UNION ALL

    (SELECT
        null as cruise_id, null as cruise_cruise_name, null as cruise_destination, null as cruise_price, null as cruise_deck,
        null as hotels_id, null as hotels_hotel_name, null as hotels_location, null as hotels_price, null as hotels_beds,
        resorts.id AS resorts_id, 
        resorts.resort AS resorts_resort, 
        resorts.location AS resorts_location, 
        resorts.price AS resorts_price,
        resorts.room_type AS resorts_room_type
    FROM resorts 
    WHERE resorts.resort LIKE '%Hawaii%')
)

在此查询结束时，您可以轻松地对结果进行排序、过滤和限制。

注意:我没有在其中包含 vacation_packages 表，因为您没有从中选择任何内容或在条件下使用它。要添加它，只需添加另一个 UNION ALL 和一个新的 SELECT 语句