Parse JSON Array of arrays to SQL table

Question

I have a JSON response from API like below:

{
  "series":[
   {
    "series_id": "SER_ID_1",
    "data": [
          ["20200101",
           1.0
          ],
          ["20200102",
           1.9
          ],
          ["20200103",
           4.5
          ]
        ]
  },
  {
    "series_id": "SER_ID_2",
    "data": [
          ["20200101",
           6.0
          ],
          ["20200102",
           8.9
          ],
          ["20200103",
           1.5
          ]
        ]
  }
 ]
}

There can be N series and there can be N values in data .

I want to parse this JSON in SQL so that I get the below results:

series_id       date        value
SER_ID_1        20200101.   1.0
SER_ID_1        20200102.   1.9
SER_ID_1        20200103.   4.5
SER_ID_2        20200101.   6.0
SER_ID_2        20200102.   8.9
SER_ID_2        20200103.   1.5

Please provide a SQL server query to get the desired result on parsing JSON.

Thanks in advance.

Answer 1

You need to parse the input JSON using OPENJSON() twice with the appropriate explicit schemas. Of course, you need SQL Server 2016+ to use the built-in JSON support.

JSON:

DECLARE @json nvarchar(max) = N'
{
  "series":[
    {
    "series_id": "SER_ID_1",
    "data": [["20200101", 1.0], ["20200102", 1.9], ["20200103", 4.5]]
    },
    {
    "series_id": "SER_ID_2",
    "data": [["20200101", 6.0], ["20200102", 8.9], ["20200103", 1.5]]
    }
  ]
}'

Statement:

SELECT j1.series_id, j2.[date], j2.[value]
FROM OPENJSON(@json, '$.series') WITH (
   series_id varchar(10) '$.series_id',
   data nvarchar(max) '$.data' AS JSON
) j1
OUTER APPLY OPENJSON(j1.data) WITH (
   [date] date '$[0]',
   [value] numeric(5, 1) '$[1]'
) j2

Result:

series_id   date       value
SER_ID_1    2020-01-01   1.0
SER_ID_1    2020-01-02   1.9
SER_ID_1    2020-01-03   4.5
SER_ID_2    2020-01-01   6.0
SER_ID_2    2020-01-02   8.9
SER_ID_2    2020-01-03   1.5