SQL Searching Query inside JSON object array - arrays

Question

Consider the below JSON object
[
{
"startdt": "10/13/2021",
"enddt": "10/13/2022",
"customerName1": "John",
"customerName2": "CA"
},
{
"startdt": "10/14/2021",
"enddt": "10/14/2022",
"customerName1": "Jacob",
"customerName2": "NJ"
}
]
This is the value present in a table "CustInfo" in the column "custjson" in Postgress DB. I want to search the data for the field customerName1. I have created the below query but it is searching in the whole object in such a way that if I give customerName1 as "Jacob" it gives the whole array. I want to search only for a particular array and return the same.
SELECT DISTINCT ON(e.id) e.*,
(jsonb_array_elements(e.custjson)->>'customerName1') AS name1
FROM CustInfo e
CROSS JOIN jsonb_array_elements(e.custjson) ej
WHERE value ->> 'customerName1' LIKE '%Jacob%'
Is there a way in which we can only search the "Jacob" customerName1's array instead of whole json?
For eg: if i search for Jacob i should get the following istead of searching the whole JSON
{
"startdt": "10/14/2021",
"enddt": "10/14/2022",
"customerName1": "Jacob",
"customerName2": "NJ"
}
Any help would be greatly helpful

Answer 1

You can use a JSON path expression to find the array element with a matching customer name:
select e.id,
jsonb_path_query_array(e.custjson, '$[*] ? (#.customerName1 like_regex "Jacob")')
from custinfo e
Based on your sample data, this returns:
id | jsonb_path_query_array
---+----------------------------------------------------------------------------------------------------
1 | [{"enddt": "10/14/2022", "startdt": "10/14/2021", "customerName1": "Jacob", "customerName2": "NJ"}]
If you are using an older Postgres version, that doesn't support JSON path queries, you need to unnest and aggregate manually:
select e.id,
(select jsonb_agg(element)
from jsonb_array_elements(e.custjson) as x(element)
where x.element ->> 'customerName1' like '%Jacob%')
from custinfo e
This assumes that custjson is defined with the data type jsonb (which it should be). If not, you need to cast it: custjson::jsonb