How to parse JSON string recursively with openjson

Question

I have the following JSON data :

set @json = N\'{
    \"Book\":{
        \"IssueDate\":\"02-15-2019\"
        , \"Detail\":{
            \"Type\":\"Any Type\"
           


        

Answer 1

I'm not sure if your expectation of the results is reasonable but clearly the returning table of your function doesn't match what you stated -- it lacks topKey column. For this reason, I'd rather aggregate the path of the hierarchy. Here we go:

create function ParseJson(
    @parent nvarchar(max), @json nvarchar(max))
returns @tempTable table (
    [key] nvarchar(max), [value] nvarchar(max))
as
begin
    ; with cte as (
        select 
            iif(@parent is null, [key]
                , concat(@parent, '.', [key])) [key]
            , [value]
        from 
            openjson(@json)
    )
    insert 
        @tempTable
    select 
        x.* 
    from 
        cte x
    union all
    select 
        x.* 
    from 
        cte y
    cross apply ParseJson(y.[key], y.[value]) x
    where isjson(y.[value])=1

    return
end

And the results: