将两个MYSQL SELECT语句合并/合并为一个

Question

我正在使用单个SELECT语句寻求帮助。 使用两个语句的示例：

第一：从现在起40天到现在的365天

第二：立即使用40天

等于所有365天，从现在起40天

选择语句1：

SELECT id FROM sales
 WHERE (saledate BETWEEN DATE_ADD(NOW(), INTERVAL 40 DAY) AND DATE_ADD(NOW(), INTERVAL 365 DAY))
 ORDER BY saledate;

选择语句2：

SELECT id FROM sales
 WHERE (saledate BETWEEN NOW() AND DATE_ADD(NOW(), INTERVAL 40 DAY))
 ORDER BY saledate;

Answer 1

您是否正在尝试使用UNION获得组合结果，例如

(SELECT id FROM sales 
WHERE (saledate BETWEEN DATE_ADD(NOW(), INTERVAL 40 DAY) 
AND DATE_ADD(NOW(), INTERVAL 365 DAY)) 
ORDER BY saledate)

UNION

(SELECT id FROM sales 
WHERE (saledate BETWEEN NOW() AND DATE_ADD(NOW(), INTERVAL 40 DAY)) 
ORDER BY saledate)

Answer 2

为什么不只是使用or ？

SELECT id
FROM sales
WHERE (saledate BETWEEN DATE_ADD(NOW(), INTERVAL 40 DAY) AND DATE_ADD(NOW(), INTERVAL 365 DAY)) OR
       (saledate BETWEEN NOW() AND DATE_ADD(NOW(), INTERVAL 40 DAY))
ORDER BY saledate;

当然，这可以进一步简化：

SELECT id
FROM sales
WHERE saledate BETWEEN (NOW() AND DATE_ADD(NOW(), INTERVAL 365 DAY)
ORDER BY saledate;

但是，这似乎很明显，我可能会丢失一些东西。

编辑：

如果这是一个订购问题，那么就不可能 union all合并。 联合不保证结果的顺序。 相反，只需执行以下操作：

SELECT id
FROM sales
WHERE saledate BETWEEN (NOW() AND DATE_ADD(NOW(), INTERVAL 365 DAY)
ORDER BY (saledate >= DATE_ADD(NOW(), INTERVAL 40 DAY) ) DESC,
         saledate;