MySQL:仅使用偶数或奇数自动递增? [英] MySQL: Auto increment with even or odd numbers only?

问题描述

是否有可能会生成自动生成偶数或奇数(跳过相反的数字)的字段?我问的原因是因为我想在两个表之间共享自动增量.其他实现它的方式也受到欢迎.

Is it possible to have auto increment field which generates even or odd numbers (skips the opposite)? The reason I am asking is because I want to share auto increment between two tables. Other ways for achieving it are welcomed.

提前谢谢！

推荐答案

您可以将一个表的自动递增字段与另一个表偏移，即，一个表的ID从1开始，而另一个表的ID从1000000开始(或者其他一些值取决于您的使用方式).

You can offset one table's auto increment field from the other, i.e. one table starts ids from 1 while the other starts from 1000000 (or some other value chosen depending on your usage pattern).

CREATE TABLE table1 (id BIGINT UNSIGNED AUTO_INCREMENT);
CREATE TABLE table2 (id BIGINT UNSIGNED AUTO_INCREMENT) AUTO_INCREMENT = 1000000;

您还可以根据需要选择自动增量列类型. BIGINT UNSIGNED的范围是0..18446744073709551615，应该可以覆盖大多数情况.

You can also choose your autoincrement column type according to your needs. BIGINT UNSIGNED's range is 0..18446744073709551615, which should cover most cases.

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