好的,首先抱歉标题,但我找不到更好的一个:(
这是问题:
我有两个表properties
和properties_rooms
,它们通过符号ID相互链接。
properties table:
+---------------+------------+
| id_properties | pr_title |
+---------------+------------+
| 1 | test |
| 2 | dummy |
+---------------+------------+
properties_rooms table:
+---------------+-------------------+--------------+----------+
| id_prop_rooms | pro_id_properties | pro_id_rooms | pro_size |
+---------------+-------------------+--------------+----------+
| 1 | 1 | 4 | 5.00 |
| 2 | 1 | 18 | 17.00 |
| 3 | 2 | 6 | 12.00 |
| 4 | 2 | 24 | 11.00 |
| 5 | 1 | 4 | 10.00 |
| 6 | 1 | 6 | 10.00 |
| 7 | 1 | 6 | 12.00 |
+---------------+-------------------+--------------+----------+
我正在进行高级搜索,用户可以搜索超过同类房间的房产(即两间卧室,三间浴室等)。
可悲的是,我发现自己陷入了困境,因为我不能用多个子句“过滤”相同的数据集;如果我只需要过滤一个就没有问题,因为我可以使用HAVING
子句。
我做了这个选择:
SELECT id_properties, pro_id_rooms, COUNT(*) as total,
IF ((pro_id_rooms = 4 AND COUNT(*) >= 2) OR (pro_id_rooms = 6 AND COUNT(*) >= 2), 1, 0) as flag
FROM `properties`
INNER JOIN properties_rooms ON id_properties = pro_id_properties
WHERE id_properties IN (4,10)
GROUP BY id_properties, pro_id_rooms
ORDER BY id_properties
在IN
子句中,有些属性我知道他们至少有一个被请求的房间。它们来自之前的查询,因为我必须使用GROUP BY
和HAVING
select中的IF
部分是在运行时构建的,因为我从请求中获取了信息
这是结果:
+---------------+--------------+-------+------+
| id_properties | pro_id_rooms | total | flag |
+---------------+--------------+-------+------+
| 1 | 4 | 2 | 1 |
| 1 | 6 | 2 | 1 |
| 1 | 18 | 1 | 0 |
| 2 | 6 | 1 | 0 |
| 2 | 24 | 1 | 0 |
+---------------+--------------+-------+------+
我认为它可以工作,我只需要添加一个HAVING flag > 0
而且我已经完成了。
我的问题是,有什么更好的吗?
表格不是很大:属性可能是1k,房间大约是10k
我担心,如果用户放置太多房间,查询将变成一个巨大的IF
声明......
答案 0 :(得分:0)
SELECT id_properties, SUM(pro_id_rooms = 4) AS bedrooms, SUM(pro_id_rooms = 6) AS bathrooms
FROM `properties`
INNER JOIN properties_rooms ON id_properties = pro_id_properties
WHERE id_properties IN (4,10)
GROUP BY id_properties
HAVING bedrooms >= 3 AND bathrooms >= 2
SUM(pro_id_rooms = 4) AS bedrooms, SUM(pro_id_rooms = 6) AS bathrooms
对于用户选择的每个复选框,您需要SUM(pro_id_rooms = x) AS nrofx
中的WHERE
。
HAVING bedrooms >= 3 AND bathrooms >= 2
这是您检查特定房间号码的地方。