Select last value from Json array

Question

I need to get the last item in an array from a JSON format. I have this JSON.

  @json =   
  N\'{ 
        \"solution\": \"xxxxxxxxxxxxxxxxxxxxx\",
        \"opt         


        

Answer 1

You can either shred with OPENJSON and re-assemble the document FOR JSON (see @digital.aaron's answer), or use JSON_MODIFY, like this:

 declare @json nvarchar(max) =   
  N'{ 
        "solution": "xxxxxxxxxxxxxxxxxxxxx",
        "options": [
            {
                "choice_id": 205073,
                "choice": "aaaa"
            },
            {
                "choice_id": 205074,
                "choice": "bbbb"
            },
            {
                "choice_id": 205075,
                "choice": "cccc"
            },
            {
                "choice_id": 205076,
                "choice": "ffffdd"
            }
        ]
    }'  


declare @options nvarchar(max) = (
    select top 1 value 
    from openjson(@json,'$.options')
    order by [key] desc 
);

set @json = json_modify(@json, '$.options', json_query(@options))

select  @json

Outputs

{ 
        "solution": "xxxxxxxxxxxxxxxxxxxxx",
        "options": {
                "choice_id": 205076,
                "choice": "ffffdd"
            }
    }

Note that the JSON_QUERY function is also used for parsing a string into a JSON fragment. Without that, the value in @options would be inserted as a single string value, instead of a json object.