(SQL Server) Download File (Stream to Local Filesystem)

This example demonstrates how to download the content of a file from Google Drive. The file is streamed to the local filesystem.

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 @success int
    SELECT @success = 1

    -- It requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- This example uses a previously obtained access token having permission for the 
    -- Google Drive scope.

    DECLARE @gAuth int
    -- Use "Chilkat_9_5_0.AuthGoogle" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.AuthGoogle', @gAuth OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OASetProperty @gAuth, 'AccessToken', 'GOOGLE_DRIVE_ACCESS_TOKEN'

    DECLARE @rest int
    -- Use "Chilkat_9_5_0.Rest" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Rest', @rest OUT

    -- Connect using TLS.
    -- A single REST object, once connected, can be used for many Google Drive REST API calls.
    -- The auto-reconnect indicates that if the already-established HTTPS connection is closed,
    -- then it will be automatically re-established as needed.
    DECLARE @bAutoReconnect int
    SELECT @bAutoReconnect = 1
    EXEC sp_OAMethod @rest, 'Connect', @success OUT, 'www.googleapis.com', 443, 1, @bAutoReconnect

    -- Provide the authentication credentials (i.e. the access token)
    EXEC sp_OAMethod @rest, 'SetAuthGoogle', @success OUT, @gAuth

    -- ------------------------------------------------------------------------------
    -- To download a file, we must know the file ID.
    -- In a previous example (see Build Local Metadata Cache
    -- we built a local cache to make it easy to lookup file IDs given a file path.
    -- Let's say we want to download "testFolder/abc/123/penguins.jpg".
    -- First we lookup the fileId in the cache.  With the fileId, we can download the file.
    DECLARE @gdCache int
    -- Use "Chilkat_9_5_0.Cache" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Cache', @gdCache OUT

    EXEC sp_OASetProperty @gdCache, 'Level', 0
    EXEC sp_OAMethod @gdCache, 'AddRoot', NULL, 'C:/ckCache/googleDrive'

    DECLARE @fileId nvarchar(4000)
    EXEC sp_OAMethod @gdCache, 'FetchText', @fileId OUT, 'testFolder/abc/123/penguins.jpg'
    EXEC sp_OAGetProperty @gdCache, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN

        PRINT 'Filepath not found in cache.'
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @gdCache
        RETURN
      END

    -- We need to send a GET request like this:
    -- GET https://www.googleapis.com/drive/v3/files/fileId?alt=media
    -- The fileId is part of the path.
    DECLARE @sbPath int
    -- Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbPath OUT

    EXEC sp_OAMethod @sbPath, 'Append', @success OUT, '/drive/v3/files/'
    EXEC sp_OAMethod @sbPath, 'Append', @success OUT, @fileId
    EXEC sp_OAMethod @rest, 'AddQueryParam', @success OUT, 'alt', 'media'

    -- Create a stream object with a SinkFile set to the path where the downloaded file will go.
    DECLARE @fileStream int
    -- Use "Chilkat_9_5_0.Stream" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Stream', @fileStream OUT

    EXEC sp_OASetProperty @fileStream, 'SinkFile', 'qa_output/penguins.jpg'
    -- Indicate that the response body should stream directly to fileStream,
    -- but only if the response status is 200.  
    EXEC sp_OAMethod @rest, 'SetResponseBodyStream', @success OUT, 200, 1, @fileStream

    -- Download the file, streaming the content to the SinkFile.
    DECLARE @jsonResponse nvarchar(4000)
    EXEC sp_OAMethod @sbPath, 'GetAsString', @sTmp0 OUT
    EXEC sp_OAMethod @rest, 'FullRequestNoBody', @jsonResponse OUT, 'GET', @sTmp0
    EXEC sp_OAGetProperty @rest, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @gdCache
        EXEC @hr = sp_OADestroy @sbPath
        EXEC @hr = sp_OADestroy @fileStream
        RETURN
      END

    -- A successful response will have a status code equal to 200.
    EXEC sp_OAGetProperty @rest, 'ResponseStatusCode', @iTmp0 OUT
    IF @iTmp0 <> 200
      BEGIN

        EXEC sp_OAGetProperty @rest, 'ResponseStatusCode', @iTmp0 OUT
        PRINT 'response status code = ' + @iTmp0

        EXEC sp_OAGetProperty @rest, 'ResponseStatusText', @sTmp0 OUT
        PRINT 'response status text = ' + @sTmp0

        EXEC sp_OAGetProperty @rest, 'ResponseHeader', @sTmp0 OUT
        PRINT 'response header: ' + @sTmp0
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @gdCache
        EXEC @hr = sp_OADestroy @sbPath
        EXEC @hr = sp_OADestroy @fileStream
        RETURN
      END


    PRINT 'File downloaded.'

    EXEC @hr = sp_OADestroy @gAuth
    EXEC @hr = sp_OADestroy @rest
    EXEC @hr = sp_OADestroy @gdCache
    EXEC @hr = sp_OADestroy @sbPath
    EXEC @hr = sp_OADestroy @fileStream


END
GO