How do I search for a specific string in a JSON Postgres data type column? - json

Question

I have a column named params in a table named reports which contains JSON.
I need to find which rows contain the text 'authVar' anywhere in the JSON array. I don't know the path or level in which the text could appear.
I want to just search through the JSON with a standard like operator.
Something like:
SELECT * FROM reports
WHERE params LIKE '%authVar%'
I have searched and googled and read the Postgres docs. I don't understand the JSON data type very well, and figure I am missing something easy.
The JSON looks something like this.
[
{
"tileId":18811,
"Params":{
"data":[
{
"name":"Week Ending",
"color":"#27B5E1",
"report":"report1",
"locations":{
"c1":0,
"c2":0,
"r1":"authVar",
"r2":66
}
}
]
}
}
]

Answer 1

In Postgres 11 or earlier it is possible to recursively walk through an unknown json structure, but it would be rather complex and costly. I would propose the brute force method which should work well:
select *
from reports
where params::text like '%authVar%';
-- or
-- where params::text like '%"authVar"%';
-- if you are looking for the exact value
The query is very fast but may return unexpected extra rows in cases when the searched string is a part of one of the keys.
In Postgres 12+ the recursive searching in JSONB is pretty comfortable with the new feature of jsonpath.
Find a string value containing authVar:
select *
from reports
where jsonb_path_exists(params, '$.** ? (#.type() == "string" && # like_regex "authVar")')
The jsonpath:
$.** find any value at any level (recursive processing)
? where
#.type() == "string" value is string
&& and
# like_regex "authVar" value contains 'authVar'
Or find the exact value:
select *
from reports
where jsonb_path_exists(params, '$.** ? (# == "authVar")')
Read in the documentation:
The SQL/JSON Path Language
jsonpath Type