mysql有没有一个算法生成一个特定id,该如何解决

mysql有没有一个算法生成一个特定id,该如何解决

mysql有没有一个算法生成一个特定id

随机生成id



没什么好办法,一种常见方法是,利用RAND随机函数生成一个,然后检查一下是否已经存在,如是存在则继续随机,直至找到一个不存在的。




mysql> select cast(rand()*100 as SIGNED );

+—————————–+

| cast(rand()*100 as SIGNED ) |

+—————————–+

| 44 |

+—————————–+

1 row in set (0.01 sec)

mysql> select cast(rand()*100 as SIGNED );

+—————————–+

| cast(rand()*100 as SIGNED ) |

+—————————–+

| 27 |

+—————————–+

1 row in set (0.00 sec)

mysql> select cast(rand()*100 as SIGNED );

+—————————–+

| cast(rand()*100 as SIGNED ) |

+—————————–+

| 1 |

+—————————–+

1 row in set (0.00 sec)

mysql有没有一个算法生成一个特定id,该如何解决

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