Convert table result to a form of JSON - sql-server-2008

Question

I am trying to form json from a table result set :
create table testmalc(
appid int identity(1,1),
propertyid1 int ,
propertyid1val varchar(10) ,
propertyid2 int,
propertyid2val varchar(10) ,
)
insert into testmalc values(456,'t1',789,'t2')
insert into testmalc values(900,'t3',902,'t4')
need below desired JSON result :
{
"data": {
"record": [{
"id": appid,
"customFields": [{
"customfieldid": propertyid1 ,
"customfieldvalue": propertyid1val
},
{
"customfieldid": propertyid2 ,
"customfieldvalue": propertyid2val
}
]
},
{
"id": appid,
"customFields": [{
"customfieldid": propertyid1 ,
"customfieldvalue": propertyid1val
},
{
"customfieldid": propertyid2 ,
"customfieldvalue": propertyid2val
}
]
}
]
}
}
I am trying to use stuff but was not getting the desired result. Now trying with UnPivot.

Answer 1

If you cannot upgrade to SQL-Server 2016 for JSON support you should try to solve this in any application / programming language you know of.
Just for fun, I provide an approach, which works, but is more a hack than a solution:
Your test data:
DECLARE #testmalc table (
appid int identity(1,1),
propertyid1 int ,
propertyid1val varchar(10) ,
propertyid2 int,
propertyid2val varchar(10)
);
insert into #testmalc values(456,'t1',789,'t2')
,(900,'t3',902,'t4');
--create a XML, which is the most similar structure and read it as a NVARCHAR string
DECLARE #intermediateXML NVARCHAR(MAX)=
(
SELECT t.appid AS id
,(
SELECT t2.propertyid1 AS [prop1/#customfieldid]
,t2.propertyid1val AS [prop1/#customfieldvalue]
,t2.propertyid2 AS [prop2/#customfieldid]
,t2.propertyid2val AS [prop2/#customfieldvalue]
FROM #testmalc t2
WHERE t2.appid=t.appid
FOR XML PATH('customFields'),TYPE
) AS [*]
FROM #testmalc t
GROUP BY t.appid
FOR XML PATH('row')
);
--Now a bunch of replacements
SET #intermediateXML=REPLACE(REPLACE(REPLACE(REPLACE(#intermediateXML,'=',':'),'/>','}'),'<prop1 ','{'),'<prop2 ','{');
SET #intermediateXML=REPLACE(REPLACE(REPLACE(REPLACE(#intermediateXML,'<customFields>','"customFields":['),'</customFields>',']'),'customfieldid','"customfieldid"'),'customfieldvalue',',"customfieldvalue"');
SET #intermediateXML=REPLACE(REPLACE(#intermediateXML,'<id>','"id":'),'</id>',',');
SET #intermediateXML=REPLACE(REPLACE(REPLACE(#intermediateXML,'<row>','{'),'</row>','}'),'}{','},{');
DECLARE #json NVARCHAR(MAX)=N'{"data":{"record":[' + #intermediateXML + ']}}';
PRINT #json;
The result (formatted)
{
"data": {
"record": [
{
"id": 1,
"customFields": [
{
"customfieldid": "456",
"customfieldvalue": "t1"
},
{
"customfieldid": "789",
"customfieldvalue": "t2"
}
]
},
{
"id": 2,
"customFields": [
{
"customfieldid": "900",
"customfieldvalue": "t3"
},
{
"customfieldid": "902",
"customfieldvalue": "t4"
}
]
}
]
}
}