mysql> select * from employee;+----+--------+--------+| id | name | salary |+----+--------+--------+| 1 | gaurav | 50000 || 2 | rahul | 20000 || 3 | advik | 25000 || 4 | aarav | 65000 || 5 | ram | 20000 || 6 | mohan | 30000 || 7 | aryan | null || 8 | vinay | null |+----+--------+--------+8 rows in set (0.00 sec)
现在，下面的查询将使用 rand() 函数，并在查询中同时使用 order by 和 limit 子句，返回随机不同的值或行集 -
mysql> select * from employee order by rand() limit 4;+----+-------+--------+| id | name | salary |+----+-------+--------+| 5 | ram | 20000 || 4 | aarav | 65000 || 6 | mohan | 30000 || 8 | vinay | null |+----+-------+--------+4 rows in set (0.00 sec)mysql> select * from employee order by rand() limit 4;+----+--------+--------+| id | name | salary |+----+--------+--------+| 6 | mohan | 30000 || 8 | vinay | null || 2 | rahul | 20000 || 1 | gaurav | 50000 |+----+--------+--------+4 rows in set (0.03 sec)mysql> select * from employee order by rand() limit 4;+----+-------+--------+| id | name | salary |+----+-------+--------+| 3 | advik | 25000 || 8 | vinay | null || 7 | aryan | null || 5 | ram | 20000 |+----+-------+--------+4 rows in set (0.00 sec)
从上面的结果集中可以看出，每次运行查询时，它都会返回一组随机不同的值或行。
以上就是我们如何每次从 mysql 表中随机获取不同的行或值集？的详细内容。