How to Insert a json value for an existing key

Question

I have a valid json doc and I want to add a new element from an existing key, whose values ​​constitute an array

set @json='{"questions":
[
  {"name":"Laptop", "price":1000},
  {"name":"Laptop", "price":2000},
  {"name":"Laptop", "price":1900},
  {"name":"Jeans",  "price":70.5}
]
}'

I want to be able to insert the element questions from this key, I tried: JSON_INSERT(@json, '$.questions', '{"name": "Other", "price": 340}'), but it does not work.

I tried:

JSON_MERGE(JSON_EXTRACT(@json, '$.questions'), '{"name": "Other", "price": 250}') The result was:

[
  {"name": "Laptop", "price": 1000},
  {"name": "Laptop", "price": 2000},
  {"name": "Laptop", "price": 1900},
  {"name": "Jeans", "price": 70.5},
  {"name": "Other", "price": 250}
]

without questions key.

I tried:

JSON_ARRAY_APPEND(@json, '$.questions', '{"name": "Other", "price": 250}')

The result was:

{"questions": 
    [
       {"name": "Laptop", "price": 1000},
       {"name": "Laptop", "price": 2000},
       {"name": "Laptop", "price": 1900},
       {"name": "Jeans", "price": 70.5},
       "{\"name\": \"Other\", \"price\": 250}"
    ]
}

AND:

JSON_INSERT(@json, CONCAT('$.questions[', JSON_LENGTH(JSON_EXTRACT(@json, '$.questions')), ']'), '{"name": "Other", "price": 250}')

Result:

{"questions": 
      [
          {"name": "Laptop", "price": 1000}, 
          {"name": "Laptop", "price": 2000}, 
          {"name": "Laptop", "price": 1900}, 
          {"name": "Jeans", "price": 70.5}, 
          "{\"name\": \"Other\", \"price\": 250}"
     ]
}

Poorly formatted, because I want to be able to do it later:

SELECT SUM(price) as total from (select * from json_table(@json, '$.questions[*]'  columns(price DOUBLE path '$.price')) as t) t

I found the solution using the following statement:

JSON_ARRAY_APPEND(@json, '$.questions[*]', JSON_OBJECT("name", "Other", "price", 39.90))