Union all，合并查询结果

Question

我有以下 MySQL 个查询：

SELECT * 
FROM bookings 
WHERE record_id = 7 AND status = 'available' AND startdate >= '2015-05-02' AND startdate <= '2015-05-09'
UNION ALL
SELECT * 
FROM bookings 
WHERE record_id = 7 AND status = 'available' AND startdate >= '2015-05-11' AND startdate <= '2015-05-12'

是否可以合并这两个查询，而不是使用 UNION ALL？

Answer 1

离开这部分：

SELECT * FROM bookings WHERE record_id = 7 AND status = 'available'

添加这个：

AND ((startdate >= '2015-05-02' AND startdate <= '2015-05-09') OR (startdate >= '2015-05-11' AND startdate <= '2015-05-12'))

如果第一个和条件或第二个和条件

为真，则条件将return为真

此外，对于您正在使用的那些和条件，您可能想看看 sql BETWEEN 语句：http://www.w3schools.com/sql/sql_between.asp

您也可以在完成第一部分后执行此操作：

AND startDate >= '2015-05-02' AND startDate <= '2015-05-12' AND NOT startDate = '2015-05-10'

因为无论如何您都在使用硬编码日期，并且该范围内您唯一不需要的日期是 5 月 10 日

Answer 2

您可以使用 OR 运算符代替

SELECT * 
FROM bookings 
WHERE record_id = 7 
AND status = 'available' 
AND ((startdate >= '2015-05-11' AND startdate <= '2015-05-12') or (startdate >= '2015-05-02' AND startdate <= '2015-05-09'))

Answer 3

这应该有效：

SELECT * 
FROM bookings 
WHERE record_id = 7 AND status = 'available' AND 
   ((startdate >= '2015-05-02' AND startdate <= '2015-05-09') or (startdate >= '2015-05-11' AND startdate <= '2015-05-12'))

Answer 4

您可以只使用 OR 运算符来获取两个日期范围：

SELECT * 
FROM   bookings 
WHERE  record_id = 7 AND
       status = 'available' AND 
       ((startdate >= '2015-05-02' AND startdate <= '2015-05-09') OR
        (startdate >= '2015-05-11' AND startdate <= '2015-05-12'))

Union all，合并查询结果

Union all, combining query results

mysql

sql

select

union-all