(更新-感谢那些评论的人)

PostgreSQL的现代版本

假设您有一个名为test1的表，希望向其添加一个自动递增的主键id(代理)列。以下命令在最新版本的PostgreSQL中应该足够了:

   ALTER TABLE test1 ADD COLUMN id SERIAL PRIMARY KEY;

PostgreSQL的旧版本

在PostgreSQL的旧版本中(在8.x之前?)你必须做所有的脏活累活。下面的命令序列应该可以达到目的:

  ALTER TABLE test1 ADD COLUMN id INTEGER;
  CREATE SEQUENCE test_id_seq OWNED BY test1.id;
  ALTER TABLE test1 ALTER COLUMN id SET DEFAULT nextval('test_id_seq');
  UPDATE test1 SET id = nextval('test_id_seq');

同样，在Postgres的最新版本中，这大致相当于上面的单个命令。

ALTER TABLE test1 ADD COLUMN id SERIAL PRIMARY KEY;

这就是你需要做的:

添加id列 用从1到count(*)的序列填充它。 设置为主键/非空。

感谢@resnyanskiy，他在评论中给出了这个答案。

I landed here because I was looking for something like that too. In my case, I was copying the data from a set of staging tables with many columns into one table while also assigning row ids to the target table. Here is a variant of the above approaches that I used. I added the serial column at the end of my target table. That way I don't have to have a placeholder for it in the Insert statement. Then a simple select * into the target table auto populated this column. Here are the two SQL statements that I used on PostgreSQL 9.6.4.

ALTER TABLE target ADD COLUMN some_column SERIAL;
INSERT INTO target SELECT * from source;

要在v10中使用标识列，

ALTER TABLE test 
ADD COLUMN id { int | bigint | smallint}
GENERATED { BY DEFAULT | ALWAYS } AS IDENTITY PRIMARY KEY;

有关标识列的解释，请参见https://blog.2ndquadrant.com/postgresql-10-identity-columns/。

关于GENERATED BY DEFAULT和GENERATED ALWAYS的区别，请参见https://www.cybertec-postgresql.com/en/sequences-gains-and-pitfalls/。

要更改序列，请参见https://popsql.io/learn-sql/postgresql/how-to-alter-sequence-in-postgresql/。

ALTER TABLE test1:添加id int8为NULL