Postgres - 在 json 元素数组中搜索

Question

My table:

id | name | open_days

Column open_days is a json column with following structure:

{
daysOfWeek: ['mon','tue','sat']
months: ['may','november']
}

I would like to find rows where daysOfWeek contain searching element. Something like

SELECT * FROM places WHERE :day=ANY(open_days->'daysOfWeek') 

But above query is not correct. Pleas help how to search is json array.

Thank you.

Answer 1

Assuming open_days is a jsonb column (which it should be), then you can use the contains operator ? :

select *
from places
where open_days -> 'daysOfWeek' ? :day

If it's a json column, you need to cast it open_days::jsonb -> ...

---

If you want to search for values that contain multiple weekdays, you can use the ?& operator:

select *
from places
where open_days -> 'daysOfWeek' ?& array['mon','tue']

the above would return all rows that contain mon and tue

Answer 2

One way is to use json_array_elements() .

SELECT *
       FROM places
       WHERE :day = ANY (SELECT json_array_elements(open_days->'daysOfWeek')#>>'{}');

Answer 3

Yet another way to do this is with the containment operator.

select * from places where open_days @> '{"daysOfWeek":["mon"]}'

An advantage over using -> ... ? is that containment can use the default JSONB index, while the other would require a specialized index.