convert rows/table records to json document in sql server

Question

the following is the sample data which is an input

if object_id('tempdb.dbo.#store_data') is not null
drop table #store_data

create table #store_data ([key] nvarchar(max),[value] nvarchar(max),storeid varchar(100)
)

INSERT INTO #store_data VALUES ('sid','1','1')
INSERT INTO #store_data VALUES ('bid','3','1');
INSERT INTO #store_data VALUES ('time','2019-01-01','1');
INSERT INTO #store_data VALUES ('que','apple','1');
INSERT INTO #store_data VALUES ('sid','2','2');
INSERT INTO #store_data VALUES ('bid','5','2');
INSERT INTO #store_data VALUES ('hrs','6','2');
INSERT INTO #store_data VALUES ('dat','pine','2');

select * from #store_data

the following is the result required

[{
"sid"="1",
"bid"="3",
"time"="2019-01-01"
"que"="apple"},
{"sid"="2",
"bid"="5",
"hrs"="6",
"dat"="pine"
}]

the following is the query which i have tried

select [key],[value] from #store_data for json path

expected results were not achieved.

Answer 1

Please note, you can't get with direct query, you have to first PIVOT on storeid.

You can try like following query.

select sid, bid, time,que, hrs,dat 
from #store_data src
pivot
(
  MAX([value])
  for [key] in (sid, bid, time,que, hrs,dat)
) piv
for json auto

Full Example

 if object_id('tempdb.dbo.#store_data') is not null
 drop table #store_data

create table #store_data ([key] nvarchar(max),[value] nvarchar(max),storeid varchar(100))

INSERT INTO #store_data VALUES ('sid','1','1')
INSERT INTO #store_data VALUES ('bid','3','1');
INSERT INTO #store_data VALUES ('time','2019-01-01','1');
INSERT INTO #store_data VALUES ('que','apple','1');
INSERT INTO #store_data VALUES ('sid','2','2');
INSERT INTO #store_data VALUES ('bid','5','2');
INSERT INTO #store_data VALUES ('hrs','6','2');
INSERT INTO #store_data VALUES ('dat','pine','2');

select sid, bid, time,que, hrs,dat 
from #store_data src
pivot
(
  MAX([value])
  for [key] in (sid, bid, time,que, hrs,dat)
) piv
for json auto

Output:

[
  {
    "sid": "1",
    "bid": "3",
    "time": "2019-01-01",
    "que": "apple"
  },
  {
    "sid": "2",
    "bid": "5",
    "hrs": "6",
    "dat": "pine"
  }
]

Online Demo:

Here

Edit:

PIVOT is automatically ordering on stroeid ASC without specifying any order. In case you want to change it to a different order let say DESC stroeid, in that case you can change the query as following.

select sid, bid, time,que, hrs,dat 
from #store_data src
pivot
(
  MAX([value])
  for [key] in (sid, bid, time,que, hrs,dat)
) piv
order by storeid desc
for json auto

Answer 2

Try this:

drop table if exists #store_data;

create table #store_data ([key] nvarchar(max),[value] nvarchar(max),storeid varchar(100)
)

INSERT INTO #store_data VALUES ('sid','1','1')
INSERT INTO #store_data VALUES ('bid','3','1');
INSERT INTO #store_data VALUES ('time','2019-01-01','1');
INSERT INTO #store_data VALUES ('que','apple','1');
INSERT INTO #store_data VALUES ('sid','2','2');
INSERT INTO #store_data VALUES ('bid','5','2');
INSERT INTO #store_data VALUES ('hrs','6','2');
INSERT INTO #store_data VALUES ('dat','pine','2');

DECLARE @DynamicTSQLStatement NVARCHAR(MAX)
       ,@ColumnNames NVARCHAR(MAX);

SELECT @ColumnNames = STUFF
(
    (
        SELECT DISTINCT ',[' + [key] + ']'
        FROM #store_data
        FOR XML PATH(''), TYPE
    ).value('.', 'NVARCHAR(MAX)')
   ,1
   ,1
   ,''
);

SET @DynamicTSQLStatement = N'
select ' + @ColumnNames + '
from #store_data
PIVOT 
(
    MAX([value]) FOR [key] IN (' + @ColumnNames + ')
) PVT
FOR JSON PATH;
';


EXEC sp_executesql @DynamicTSQLStatement;

Change to SELECT * in order to get the storeid in the JSON object, too. Also, in SQL Server 2017 you can use STRING_AGG to concatenate the keys.