(SQL Server) Get the Root of a JSON Document

Demonstrates how to get back to the JSON root object from anywhere in the JSON document. This example uses the following JSON document:

{
  "flower": "tulip",
  "abc":
    {
    "x": [
       { "a" : 1 },
       { "b1" : 100, "b2" : 200 },
       { "c" : 3 }
    ],
    "y": 200,
    "z": 200
    }
}

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @json int
    -- Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @json OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @jsonStr nvarchar(4000)
    SELECT @jsonStr = '{"flower": "tulip","abc":{"x": [{ "a" : 1 },{ "b1" : 100, "b2" : 200 },{ "c" : 3 }],"y": 200,"z": 200}}'

    DECLARE @success int
    EXEC sp_OAMethod @json, 'Load', @success OUT, @jsonStr
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @json, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @json
        RETURN
      END

    -- Get the "abc" object.
    DECLARE @abcObj int
    EXEC sp_OAMethod @json, 'ObjectOf', @abcObj OUT, 'abc'
    EXEC sp_OAGetProperty @json, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN

        PRINT 'abc object not found.'
        EXEC @hr = sp_OADestroy @json
        RETURN
      END

    -- Side note: The JSON of a sub-part of the document can be emitted from any JSON object:
    EXEC sp_OASetProperty @abcObj, 'EmitCompact', 0
    EXEC sp_OAMethod @abcObj, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- Navigate to the "x" array
    DECLARE @xArray int
    EXEC sp_OAMethod @abcObj, 'ArrayOf', @xArray OUT, 'x'
    -- We'll skip the null check and assume it's non-null...

    -- Navigate to the 2nd object contained within the array.  This contains members b1 and b2
    DECLARE @bObj int
    EXEC sp_OAMethod @xArray, 'ObjectAt', @bObj OUT, 1
    -- We'll skip the null check and assume it's non-null...

    -- Show that we're at "b1/b2".
    -- The value of "b1" should be "200"

    EXEC sp_OAMethod @bObj, 'IntOf', @iTmp0 OUT, 'b2'
    PRINT 'b2 = ' + @iTmp0

    -- Now go back to the JSON doc root:
    DECLARE @docRoot int
    EXEC sp_OAMethod @bObj, 'GetDocRoot', @docRoot OUT
    -- We'll skip the null check and assume it's non-null...

    -- Pretty-print the JSON doc from the root to show that this is indeed the root.
    EXEC sp_OASetProperty @docRoot, 'EmitCompact', 0
    EXEC sp_OAMethod @docRoot, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    EXEC @hr = sp_OADestroy @docRoot

    EXEC @hr = sp_OADestroy @bObj

    EXEC @hr = sp_OADestroy @xArray

    EXEC @hr = sp_OADestroy @abcObj


    EXEC @hr = sp_OADestroy @json


END
GO