时间:2021-07-01 10:21:17 帮助过:14人阅读
可以使用IN子句来代替相结合的“大于等于和小于等于”的条件。
要了解BETWEEN 子句考虑的EMPLOYEE_TBL表有以下记录:
mysql> SELECT * FROM employee_tbl; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 2007-01-24 | 250 | | 2 | Ram | 2007-05-27 | 220 | | 3 | Jack | 2007-05-06 | 170 | | 3 | Jack | 2007-04-06 | 100 | | 4 | Jill | 2007-04-06 | 220 | | 5 | Zara | 2007-06-06 | 300 | | 5 | Zara | 2007-02-06 | 350 | +------+------+------------+--------------------+ 7 rows in set (0.00 sec)
现在,假设根据上表想获取记录条件daily_typing_pages超过170,等于和小于300。这可以使用如下条件>=和<=
mysql>SELECT * FROM employee_tbl ->WHERE daily_typing_pages >= 170 AND ->daily_typing_pages <= 300; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 2007-01-24 | 250 | | 2 | Ram | 2007-05-27 | 220 | | 3 | Jack | 2007-05-06 | 170 | | 4 | Jill | 2007-04-06 | 220 | | 5 | Zara | 2007-06-06 | 300 | +------+------+------------+--------------------+ 5 rows in set (0.03 sec)
同样可以实现使用BETWEEN子句如下:
mysql> SELECT * FROM employee_tbl -> WHERE daily_typing_pages BETWEEN 170 AND 300; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 2007-01-24 | 250 | | 2 | Ram | 2007-05-27 | 220 | | 3 | Jack | 2007-05-06 | 170 | | 4 | Jill | 2007-04-06 | 220 | | 5 | Zara | 2007-06-06 | 300 | +------+------+------------+--------------------+ 5 rows in set (0.03 sec)