MySQL - 需要更好的查询解决方案，极端加载时间

Question

我有两张桌子 - ＆gt;公寓和可用性。

在公寓中，有关于公寓的所有信息。在表格可用性中，有关于未来365天公寓可用性的所有信息。

表公寓：

id, name

实施例：

1, Apartment 1
2, Apartment 2

表格可用性：

id, apartment_id, date, status

实施例：

1, 1, 2017-06-01, free
2, 1, 2017-06-02, booked
3, 1, 2017-06-03, free
4, 1, 2017-06-04, free
5, 1, 2017-06-05, free
...
6, 2, 2017-06-05, free
7, 2, 2017-06-05, free
8, 2, 2017-06-05, free
9, 2, 2017-06-05, booked
10, 2, 2017-06-05, free
...

现在我希望在多个日期范围内搜索免费公寓一周，如：

SELECT apartments where id in (
    SELECT apartment_id 
    FROM availabilities 
    WHERE EXISTS (
        SELECT apartment_id 
        FROM availabilities as a 
        WHERE availabilities.apartment_id = a.apartment_id 
        AND date >= "2017-06-01" 
        AND date < "2017-06-08" 
        AND status = "free" 
        GROUP BY apartment_id 
        HAVING COUNT(apartment_id) = DATEDIFF("2017-06-08", "2017-06-01")) 
    OR EXISTS (
        SELECT apartment_id 
        FROM availabilities as a 
        WHERE availabilities.apartment_id = a.apartment_id 
        AND date >= "2017-06-02" 
        AND date < "2017-06-09" 
        AND status = "free" 
        GROUP BY apartment_id HAVING COUNT(apartment_id) = DATEDIFF("2017-06-09", "2017-06-02"))`

这应该查找日期范围内一周的所有可能性（2017-06-01 - 2017-06-30）

我的问题是，我们有很多公寓，这个查询的加载时间非常长。

任何有关更好解决方案的想法？

Answer 1

使用（COUNT（*）和过滤器修复状态=＆＃34;预订＆＃34;）= 0

查询速度提高了30％。