sql - Postgres 数组前缀匹配

Question

我在 Postgres 中有一个数组搜索，至少匹配一个标签，如下所示：

SELECT * FROM users WHERE tags && ['fun'];

| id | tags      |
| 1  | [fun,day] | 
| 2  | [fun,sun] |

可以匹配前缀吗？就像是：

SELECT * FROM users WHERE tags LIKE 'f%';

| id | tags      |
| 1  | [fun,day] | 
| 2  | [fun,sun] |
| 3  | [far]     | 
| 4  | [fin]     |

Answer 1

尝试这个

create table users (id serial primary key, tags text[]);

insert into users (tags)
values
  ('{"fun", "day"}'),
  ('{"fun", "sun"}'),
  ('{"test"}'),
  ('{"fin"}');

select *
from users
where exists (select * from unnest(tags) as arr where arr like 'f%')

SQL 提琴示例

Answer 2

这是一个工作示例，应该或多或少地为您提供所需的东西。请注意，我并不是说这种方法可以扩展......

create table users (
id      serial primary key,
tags    text[] not null
);

insert into users (tags) values
('{"aaaa","bbbb","cccc"}'::text[]),
('{"badc","dddd","eeee"}'::text[]),
('{"gggg","ffbb","attt"}'::text[]);

select *
from (select id,unnest(tags) arr from users) u
where u.arr like 'a%';

 id | arr  
----+------
  1 | aaaa
  3 | attt