SQL Server 2017 Selecting JSON embedded within a JSON field

Question

In SQL Server 2017, I'd like to "SELECT" a JSON object embedded within another as a string so we can store/process them later.
eg JSON:

[
{"key1":"value1",
"level2_Obj":{"key2":"value12"}
},
{"key1":"value2",
"level2_Obj":{"key22":"value22"}
},
]

From above JSON, I'd like to SELECT whole of the level2Obj JSON object, see below for what I'd like to see the "selection" result.

value1  |{"key2" :"value12"}
value2  |{"key22":"value22"} 

I tried below with no luck:

SELECT * FROM
OPENJSON(@json,'$."data1"')
WITH( 
    [key1]      nvarchar(50),
    [embedded_json]     nvarchar(max)   '$."level2Obj"'
) AS DAP 

Can some one please help how I select the contents of the 2nd level JSON object as a string?
The idea is to Write 1st level JSON properties into individual cells and rest of JSON levels into a single column of type nvarchar(max) (ie whole of sub-level JSON object into a single column as a string for further processing in later stages).

Answer 1

Good day,

Firstly, Your JSON text is not properly formatted. There is extra comma after the last object in the array. I will remove this extra comma for the sake of the answer, but if this is the format you have then first step will be to clear the text and make sure that is is well formatted.

Please check if this solve your needs:

declare @json nvarchar(MAX) = '
[
{
"key1":"value1",
"level2_Obj":{"key2":"value12"}
}
,
{
"key1":"value2",
"level2_Obj":{"key22":"value22"}
}
]
'
SELECT JSON_VALUE (t1.[value], '$."key1"'), JSON_QUERY (t1.[value], '$."level2_Obj"')
FROM OPENJSON(@json,'$') t1