Transpose a array that is in a json file into columns - arrays

Question

I have a JSON where in between is an array. I already extracted all the other information in the json but i cant do it with the array in it. IT looks like this in BigQuery and it is a String JSON
{
"description":"Eminem.",
"eDate":{
"_seconds":1673668800,"_nanoseconds":409000000
},
"pId":"test-plan-1",
"Id":"test-p-1",
"startDate":{
"_seconds":1673636400,"_nanoseconds":957000000
},
"Categories":[
{
"description":"Eminem 123.",
"id":"cheap",
"name":"Cheap Ticket", "sEnd":{"_seconds":1767283200,"_nanoseconds":225000000},
"sStart":{"_seconds":1673272800,"_nanoseconds":330000000},
"tRate":0.19,
"uPrice":1.5
}
],
"title":"Apple",
"vId":"test-v-1"
}
The array starts by categories and end by uPrice
Im expecting that all keys with their values have their own column . The data from JSON and from the array

Answer 1

One possible way would be using JSON_QUERY_ARRAY with ARRAY_TO_STRING. JSON_QUERY_ARRAY returns ARRAY<STRING> which cannot be directly parsed again.
Below is the result of the following query.
WITH
json_dataset AS (
SELECT '{"description":"Eminem.","eDate":{"_seconds":1673668800,"_nanoseconds":409000000},"pId":"test-plan-1","Id":"test-p-1","startDate":{"_seconds":1673636400,"_nanoseconds":957000000},"Categories":[{"description":"Eminem 123.","id":"cheap","name":"Cheap Ticket", "sEnd":{"_seconds":1767283200,"_nanoseconds":225000000},"sStart":{"_seconds":1673272800,"_nanoseconds":330000000},"tRate":0.19,"uPrice":1.5}],"title":"Apple","vId":"test-v-1"}' as json_string
)
SELECT
json_string,
JSON_VALUE(
json_string,'$.description'
) AS json_value_col,
JSON_QUERY_ARRAY(
json_string,'$.Categories'
) AS json_query_array_col,
ARRAY_TO_STRING(
JSON_QUERY_ARRAY(
json_string,'$.Categories'
),
""
) AS json_array_string,
JSON_VALUE(
ARRAY_TO_STRING(JSON_QUERY_ARRAY(json_string,'$.Categories'),""),'$.description'
) AS target_example,
FROM json_dataset
;