Postgres：添加 ENUM 值的描述？

Question

我在 Postgres 9.6 中有一篇ENUM专栏：

CREATE TYPE my_type AS ENUM('foo', 'bar');

我想为枚举中的每个值添加人类可读的描述，例如 for foo, This is the foo value and it does stuff。

在 Postgres 中有什么办法可以做到这一点吗？我想要类似 Django's choice field的东西。

Answer 1

我认为没有什么花哨的事情可以做。标准comment？..

t=# \x
Expanded display is on.
t=# comment on type my_type is 'foo: something fooish, bar: a place to avoid';
COMMENT
t=# \dT+ my_type
List of data types
-[ RECORD 1 ]-----+---------------------------------------------
Schema            | public
Name              | my_type
Internal name     | my_type
Size              | 4
Elements          | foo                                         +
                  | bar
Owner             | postgres
Access privileges |
Description       | foo: something fooish, bar: a place to avoid

一些书呆子的狙击：

t=# comment on type my_type is '{"foo": "something fooish", "bar": "a place to avoid"}';
COMMENT
t=# select pg_catalog.obj_description(t.oid, 'pg_type')::json->>'foo' from pg_type t where typname = 'my_type';
     ?column?
------------------
 something fooish
(1 row)