parsing json values in sql server - json

Question

I want to parse the below json values.
DECLARE #json NVARCHAR(MAX)
SET #json =
N'[{"ID":1,"Roles":[1,2]},{"ID":2"Roles":[1,2,3]},{"ID":3,"Roles":[1,2,3,4]}]'
i want to display below output
Required Output
ID ROLES
1 1
1 2
2 1
2 2
2 3
3 1
3 2
3 3
3 4
I want query for this.

Answer 1

An OPENJSON with a WITH unrolls the outer layer, then a regular one can be used to unroll the arrays. (The alias isn't strictly necessary, I just think it's clearer, and it becomes necessary if you have to peel even more layers.)
SELECT ID, R.[Value] AS [Role]
FROM OPENJSON(#json) WITH (
ID INT,
[Roles] NVARCHAR(MAX) AS JSON
)
CROSS APPLY OPENJSON([Roles]) R

Answer 2

Try this:
DECLARE #json NVARCHAR(MAX)
SET #json =
N'[{"ID":1,"Roles":[1,2]},{"ID":2, "Roles":[1,2,3]},{"ID":3,"Roles":[1,2,3,4]}]'
SELECT pvt.[ID]
,roles.value
FROM
(
SELECT js.[key] as [key_id]
,roles.[key]
,roles.value
FROM OPENJSON(#json) js
CROSS APPLY OPENJSON(js.value) roles
) DS
PIVOT
(
MAX([value]) FOR [key] IN ([ID], [Roles])
) PVT
CROSS APPLY OPENJSON(pvt.roles) roles
or just this:
SELECT JSON_VALUE(js.value, '$.ID')
,ds.[value]
FROM OPENJSON(#json) js
CROSS APPLY OPENJSON(JSON_QUERY(js.value, '$.Roles')) ds;