UUID

PostgreSQL 支持 UUID 类型。

通常，使用 uuid-ossp 模块提供的函数来生成 UUID。

使用 CREATE EXTENSION 语句来安装 uuid-ossp 模块：

CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

SELECT uuid_generate_v4();
/* 结果
           uuid_generate_v4
--------------------------------------
 8896dab8-0d65-418c-a74e-a025307ef603
(1 row)
*/

创建一张使用 UUID 为主键的表：

CREATE TABLE contacts (
    contact_id uuid DEFAULT uuid_generate_v4 (),
    first_name VARCHAR NOT NULL,
    last_name VARCHAR NOT NULL,
    email VARCHAR NOT NULL,
    phone VARCHAR,
    PRIMARY KEY (contact_id)
);

INSERT INTO contacts (
    first_name,
    last_name,
    email,
    phone
)
VALUES
    (
        'John',
        'Smith',
        '[email protected]',
        '408-237-2345'
    ),
    (
        'Jane',
        'Smith',
        '[email protected]',
        '408-237-2344'
    ),
    (
        'Alex',
        'Smith',
        '[email protected]',
        '408-237-2343'
    );

SELECT * FROM contacts;

/* 结果
              contact_id              | first_name | last_name |         email          |    phone
--------------------------------------+------------+-----------+------------------------+--------------
 9815c410-80b6-4309-b4e7-c47ec638da6f | John       | Smith     | [email protected] | 408-237-2345
 f51d0b1d-c221-405f-a09b-04c68df1f0c8 | Jane       | Smith     | [email protected] | 408-237-2344
 2ead7c0b-cfb0-4c0c-b137-2ce239f3b4d6 | Alex       | Smith     | [email protected] | 408-237-2343
(3 rows)
*/