SQL Server - parse json with multiple objects - json

Question

I'm parsing a JSON dataset within SQL Server and it works great with a single object, but falls down when multiple data objects are presented. I assume it's because of the CROSS APPLY statements.
Within the JSON dataset, there is only 4 records, but my current sql is returning 16 (4 duplicate sets, as there are 4 cross apply statements), but I'm not sure how to get around this?
json
{
"type": "test",
"user": {
"last_update": "2022-06-19T14:13:07.707502+00:00",
"user_id": "12345"
},
"data": [
{
"metadata": {
"start_time": "2022-06-19T00:00:00+01:00",
"end_time": "2022-06-20T00:00:00+01:00"
},
"distance_data": {
"steps": 9299,
"distance_meters": 7704.0
}
},
{
"metadata": {
"start_time": "2022-06-17T00:00:00+01:00",
"end_time": "2022-06-18T00:00:00+01:00"
},
"distance_data": {
"steps": 2546,
"distance_meters": 2143.0
}
},
{
"metadata": {
"start_time": "2022-06-16T00:00:00+01:00",
"end_time": "2022-06-17T00:00:00+01:00"
},
"distance_data": {
"steps": 4969,
"distance_meters": 4192.0
}
},
{
"metadata": {
"start_time": "2022-06-18T00:00:00+01:00",
"end_time": "2022-06-19T00:00:00+01:00"
},
"distance_data": {
"steps": 6769,
"distance_meters": 5698.0
}
}
]
}
SQL statement
SELECT
distance_meters, steps, cast(left(start_time,10) as date) startDate
FROM
OPENJSON ( #json )
WITH (
jType nvarchar(50) N'$.type',
jUser char(36) N'$.user.user_id',
data nvarchar(max) as JSON
) as a
CROSS APPLY
OPENJSON(a.data)
WITH
(
distance_data nvarchar(max) as json
) as b
CROSS APPLY
OPENJSON (b.distance_data)
WITH
(
distance_meters float,
steps int
) as c
CROSS APPLY
OPENJSON (a.data)
WITH
(
metadata nvarchar(max) as json
) as d
CROSS APPLY
OPENJSON (d.metadata)
WITH
(
start_time nvarchar(25),
end_time nvarchar(25)
) as e
ORDER BY startDate ASC;

Answer 1

I think you need a single APPLY operator:
SELECT j1.jType, j1.jUser, j2.*
FROM OPENJSON(#json) WITH (
jType nvarchar(50) N'$.type',
jUser char(36) N'$.user.user_id',
data nvarchar(max) as JSON
) AS j1
CROSS APPLY OPENJSON(j1.data) WITH (
start_time nvarchar(25) '$.metadata.start_time',
end_time nvarchar(25) '$.metadata.end_time',
steps numeric(10, 0) '$.distance_data.steps',
distance_meters numeric(10, 1) '$.distance_data.distance_meters'
) j2
Result:
jType
jUser
start_time
end_time
steps
distance_meters
test
12345
2022-06-19T00:00:00+01:00
2022-06-20T00:00:00+01:00
9299
7704.0
test
12345
2022-06-17T00:00:00+01:00
2022-06-18T00:00:00+01:00
2546
2143.0
test
12345
2022-06-16T00:00:00+01:00
2022-06-17T00:00:00+01:00
4969
4192.0
test
12345
2022-06-18T00:00:00+01:00
2022-06-19T00:00:00+01:00
6769
5698.0