postgresql - 在 PostgreSQL 中生成自动递增主键的可接受方法是什么？

Question

没有序列和触发器就没有简单的方法吗？我的 SQL 技能一般，我想使用 pl/sql (PostgreSQL) 的行业标准方法。我基本上是从 Spring Security 转换这个示例表:

create table group_members (
    id bigint generated by default as identity(start with 0) primary key,
    username varchar(50) not null,
    group_id bigint not null,
    constraint fk_group_members_group foreign key(group_id) references groups(id));

我目前拥有的:

CREATE TABLE auth_group_members (
    id NUMBER,
    username VARCHAR(50) NOT NULL,
    group_id NUMBER NOT NULL,
    CONSTRAINT "FK_AuthGroupMembers" FOREIGN KEY(group_id) REFERENCES auth_groups(id)
);

Answer 1

标准方法是使用 serial or bigserial :

The data types serial and bigserial are not true types, but merely a notational convenience for creating unique identifier columns (similar to the AUTO_INCREMENT property supported by some other databases).
[...]
Thus, we have created an integer column and arranged for its default values to be assigned from a sequence generator.

所以你会用这样的东西创建表:

CREATE TABLE auth_group_members (
    id bigserial primary key,
    username VARCHAR(50) NOT NULL,
    group_id NUMBER NOT NULL,
    CONSTRAINT "FK_AuthGroupMembers" FOREIGN KEY(group_id) REFERENCES auth_groups(id)
);

serial 和 bigserial 类型确实在幕后创建了一个序列，但您永远不必直接使用该序列。