确保唯一ID的PostgreSQL序列 [英] PostgreSQL sequence that ensure a unique ID

问题描述

具有一个表，该表的列ID为主键，而列MyNumber包含由序列myUniqueSequence定义的整数。我想在PostgreSQL中定义myUniqueSequence，它将为MyNumber列返回下一个唯一的自由编号。

Having a table with a columnn ID as primary key, and a column MyNumber that contains integers defined by the sequence myUniqueSequence. I would like to define myUniqueSequence in PostgreSQL that will return the next free and unique number for the column MyNumber.

这意味着，下次以编程方式创建新行时，从数字1开始，如果免费，它将用于myNumber列，否则将尝试2，依此类推。

This means, the next time a new row is created programatically will start by number 1, if it's free it will use it for the column myNumber, if not, it tries with 2 and so on.

推荐答案

对列使用 serial 数据类型（而不是您自己的序列）：

Use the serial data type for your column (instead of your own sequence):

http://www.postgresql.org/docs/9.0/static/datatype-numeric.html ＃DATATYPE-SERIAL

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