如何检查字符串是否包含在数组中？

Question

在我的PostgreSQL数据库（ version: 11.4 ）中，我有一个名为table_1的表，它只有一列。 此列的数据类型是字符串数组 ( _varchar )。

| dependencies   |
|----------------|
|{\1}            | 
|{\1,\1\2}       |
|{\1,\1\2,\1\2\3}|

另外，我有一个名为table_2的表，它具有这样的结构：

| employee       | dependence |
|----------------|------------|
| Alex           | \1         |
| Mark           | \1         |
| Lily           | \1\2       |
| Grace          | \1\2       |
| Evie           | \1\2       |
| Bob            | \1\2\3     |
| Mark           | \1\2       |

如何检查字符串是否包含在数组中？ 就我而言，我尝试检查table_2的dependence列值是否存在于table_1的dependencies列的数组中。

换句话说，我试图得到这样的结果：

| dependencies   | total |
|----------------|-------|
|{\1}            | 2     | 
|{\1,\1\2}       | 6     |
|{\1,\1\2,\1\2\3}| 7     |

我尝试过的 SQL 请求：

select
    table_1.dependencies,
    calculation.total
from
    table_1
join lateral (
    select
        count(*) as total
    from
        table_2
    where
        table_2.dependence in table_1.dependencies /* ? */
) calculation on 1 = 1

Answer 1

用字段TEXT[]试试这个

select dependencies ,count(*) from table_1 join table_2
on dependence  = ANY( dependencies)
group by 1

表格1

create table table_1
(
    dependencies text[]
);
insert into public.table_1 (dependencies) values ('{1}');
insert into public.table_1 (dependencies) values ('{1,12}');
insert into public.table_1 (dependencies) values ('{1,12,123}');

表_2

create table if not exists table_2
    (
        employee varchar,
        dependence text
    );
insert into public.table_2 (employee, dependence) values ('Mark', 12);
insert into public.table_2 (employee, dependence) values ('Lily', 12);
insert into public.table_2 (employee, dependence) values ('Evie', 12);
insert into public.table_2 (employee, dependence) values ('Alex', 1);
insert into public.table_2 (employee, dependence) values ('Mark', 1);
insert into public.table_2 (employee, dependence) values ('Grace', 12);
insert into public.table_2 (employee, dependence) values ('Bob', 123);