SQL Server 2016 - Array into separate columns - arrays

Question

I'm tasked with importing data into SQL thats pretty much JSON but not quite . I've used OPENROWSET/OPENJSON to import into a staging table and the data looks like this
What I need to achieve is migrate that to a single table with the following structure
I'm having no success , I even trying updating the data in the staging table to look like this and import but no joy.
My current attempt:
SELECT A.[DATE], A.[VALUE]
FROM OPENJSON(#JSON) AS I
CROSS APPLY (
SELECT *
FROM OPENJSON (#JSON) WITH (
[DATE] NVARCHAR(MAX) '$.DATE',
[VALUE] NVARCHAR(MAX) '$.VALUE'
)
) A OUTPUT
Any recommendations ?

Answer 1

Just use this way:
CREATE TABLE #tmp (
instance NVARCHAR(50),
json NVARCHAR(1000)
)
INSERT #tmp
VALUES
( N'server1.com',
N'[{"date":10000, "value":"6"},{"date":20000, "value":"8"}]'
)
SELECT
t.instance, Date,Value
FROM #tmp t
OUTER APPLY OPENJSON(t.json)
WITH (
Date varchar(200) '$.date' ,
Value VARCHAR(100) '$.value'
)

Answer 2

For your first set of data, you have a doubly-nested JSON array, so you need to use OPENJSON to break open the outer one first:
SELECT
instance
JSON_VALUE(j1.innerArray, '$[0]') AS date,
JSON_VALUE(j1.innerArray, '$[1]') AS value
FROM table t
CROSS APPLY OPENJSON(t.json) WITH (
innerArray nvarchar(max) '$' AS JSON
) j1
For the second version, just change the JSON_VALUE parameters:
JSON_VALUE(j1.innerArray, '$.date') AS date,
JSON_VALUE(j1.innerArray, '$.value') AS value

Answer 3

Original answer:
The reason for the unexpected result is the fact, that the you have nested JSON arrays, but the WITH clause is not correct. You need to use the appropriate WITH clause, like the statement below:
Table:
SELECT *
INTO Data
FROM (VALUES
('server1.com', '[[1613347200, "7"], [1613347205, "8"], [1613347202, "9"]]'),
('server2.com', '[[1613317200, "3"], [1613347215, "2"], [1613347212, "1"]]')
) v (instance, array)
Statement:
SELECT d.instance, j.[date], j.[value]
FROM Data d
OUTER APPLY OPENJSON(d.array) WITH (
[date] numeric(10, 0) '$[0]',
[value] varchar(1) '$[1]'
) j
Result:
instance date value
-----------------------------
server1.com 1613347200 7
server1.com 1613347205 8
server1.com 1613347202 9
server2.com 1613317200 3
server2.com 1613347215 2
server2.com 1613347212 1
Update:
Your second attempt is almost correct. The reason for the NULL values is the fact, that the path part of the columns definitions in the WITH clause is case sensitive:
SELECT d.instance, j.[date], j.[value]
FROM (VALUES
('server1.com', '[{"date":1613347200, "value":"7"}, {"date":1613347200, "value":"8"}]')
) d (instance, array)
OUTER APPLY OPENJSON(d.array) WITH (
[date] numeric(10, 0) '$.date',
[value] varchar(1) '$.value'
) j