SQL server query on json string for stats - sql

Question

I have this SQL Server database that holds contest participations. In the Participation table, I have various fields and a special one called ParticipationDetails. It's a varchar(MAX). This field is used to throw in all contest specific data in json format. Example rows:
Id,ParticipationDetails
1,"{'Phone evening': '6546546541', 'Store': 'StoreABC', 'Math': '2', 'Age': '01/01/1951'}"
2,"{'Phone evening': '6546546542', 'Store': 'StoreABC', 'Math': '2', 'Age': '01/01/1952'}"
3,"{'Phone evening': '6546546543', 'Store': 'StoreXYZ', 'Math': '2', 'Age': '01/01/1953'}"
4,"{'Phone evening': '6546546544', 'Store': 'StoreABC', 'Math': '3', 'Age': '01/01/1954'}"
I'm trying to get a a query runing, that will yield this result:
Store, Count
StoreABC, 3
StoreXYZ, 1
I used to run this query:
SELECT TOP (20) ParticipationDetails, COUNT(*) Count FROM Participation GROUP BY ParticipationDetails ORDER BY Count DESC
This works as long as I want unique ParticipationDetails. How can I change this to "sub-query" into my json strings. I've gotten to this query, but I'm kind of stuck here:
SELECT 'StoreABC' Store, Count(*) Count FROM Participation WHERE ParticipationDetails LIKE '%StoreABC%'
This query gets me the results I want for a specific store, but I want the store value to be "anything that was put in there".
Thanks for the help!

Answer 1

first of all, I suggest to avoid any json management with t-sql, since is not natively supported. If you have an application layer, let it to manage those kind of formatted data (i.e. .net framework and non MS frameworks have json serializers available).
However, you can convert your json strings using the function described in this link.
You can also write your own query which works with strings. Something like the following one:
SELECT
T.Store,
COUNT(*) AS [Count]
FROM
(
SELECT
STUFF(
STUFF(ParticipationDetails, 1, CHARINDEX('"Store"', ParticipationDetails) + 9, ''),
CHARINDEX('"Math"',
STUFF(ParticipationDetails, 1, CHARINDEX('"Store"', ParticipationDetails) + 9, '')) - 3, LEN(STUFF(ParticipationDetails, 1, CHARINDEX('"Store"', ParticipationDetails) + 9, '')), '')
AS Store
FROM
Participation
) AS T
GROUP BY
T.Store