Get keys into JSON column in SQL Server 2017

Question

I have this Json in a column of type NVARCHAR(MAX) in SQL Server 2017:

{
    "coreTimes": {
        "TMP_CLINICAL_TIMES_ANESTHESIOLOGY_OUT_DATETIME": {
            "value": 1
        },
        "TMP_CLINICAL_TIMES_ANESTHESIOLOGY_IN_DATETIME": {
            "value": 2
        },
        "TMP_CLINICAL_TIMES_SURGICAL_OUT_DATETIME": {
            "value": 3
        },
        "TMP_CLINICAL_TIMES_ROOM_IN_DATETIME": {
            "value": 4
        },
        "TMP_CLINICAL_TIMES_ROOM_OUT_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_BLOCK_OUT_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_BLOCK_IN_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_SURGICAL_IN_DATETIME": {
            "value": null
        }
    }
}

I need this result:

Column
{"value":1}
{"value":2}
{"value":3}
{"value":4}
{"value":null}
{"value":null}
{"value":null}

What SQL Server 2017 function can I use to get this result if json properties can change dynamically (the key 'coreTimes' is fixed)?

In Oracle I have used:

 SELECT res.*
 FROM sopinterventionsaux   ,
      JSON_TABLE ( operating_times, '$.coreTimes.*'
           COLUMNS (
              value VARCHAR2 ( 2000 ) FORMAT JSON PATH '$'
                    )
                ) res

In PostgreSQL:

select value from table, jsonb_each(column-> 'coreTimes')

And in SQL Server?

Answer 1

If I understand you correctly, you need to use OPENJSON() with default schema to parse the input JSON . In this case OPENJSON() returns a table with columns key , value and type :

Table:

DECLARE @json nvarchar(max) = N'{
    "coreTimes": {
        "TMP_CLINICAL_TIMES_ANESTHESIOLOGY_OUT_DATETIME": {
            "value": 1
        },
        "TMP_CLINICAL_TIMES_ANESTHESIOLOGY_IN_DATETIME": {
            "value": 2
        },
        "TMP_CLINICAL_TIMES_SURGICAL_OUT_DATETIME": {
            "value": 3
        },
        "TMP_CLINICAL_TIMES_ROOM_IN_DATETIME": {
            "value": 4
        },
        "TMP_CLINICAL_TIMES_ROOM_OUT_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_BLOCK_OUT_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_BLOCK_IN_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_SURGICAL_IN_DATETIME": {
            "value": null
        }
    }
}'

CREATE TABLE Data (JsonData nvarchar(max))
INSERT INTO Data (JsonData) VALUES (@json)

Statement:

SELECT j.[value]
FROM Data d
CROSS APPLY OPENJSON(d.JsonData, '$.coreTimes') j

Result:

---------------
value
---------------
{"value": 1}
{"value": 2}
{"value": 3}
{"value": 4}
{"value": null}
{"value": null}
{"value": null}
{"value": null}

If you want to get the exact values for the value keys, you need to use OPENJSON() with explicit schema (with columns definitions) and additional APPLY operator.

Statement:

SELECT j2.[value]
FROM Data d
CROSS APPLY OPENJSON(d.JsonData, '$.coreTimes') j1
CROSS APPLY OPENJSON(j1.[value]) WITH ([value] int '$.value') j2

Result:

-----
value
-----
1
2
3
4
NULL
NULL
NULL
NULL

Answer 2

Please try following:

declare @j nvarchar(max) = '{
    "coreTimes": {
        "TMP_CLINICAL_TIMES_ANESTHESIOLOGY_OUT_DATETIME": {
            "value": 1
        },
        "TMP_CLINICAL_TIMES_ANESTHESIOLOGY_IN_DATETIME": {
            "value": 2
        },
        "TMP_CLINICAL_TIMES_SURGICAL_OUT_DATETIME": {
            "value": 3
        },
        "TMP_CLINICAL_TIMES_ROOM_IN_DATETIME": {
            "value": 4
        },
        "TMP_CLINICAL_TIMES_ROOM_OUT_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_BLOCK_OUT_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_BLOCK_IN_DATETIME": {
            "value": null
        },
        "TMP_CLINICAL_TIMES_SURGICAL_IN_DATETIME": {
            "value": null
        }
    }
}'

select L1.[Value] from OPENJSON (@j, '$.coreTimes') AS L1