Read file content as Base64

Reads file content as a Base64 string. Also demonstrates saving Base64 to disk to recreate the file.

Standard SQL query example

This is the base query accepted by the connector. To execute it in SQL Server, you have to pass it to the Data Gateway via a Linked Server. See how to accomplish this using the examples below.

SELECT Data as BYTES_AS_BASE64_STRING, BASE64_TO_FILE('C:\My files\Employees\List.xls', Data) FILE_SAVED_TO_DISK_FROM_BASE64 
FROM download_file
WITH (
   -- Drive (SharePoint Document Library)
	  DriveId='b!GtLN726LE0eY5F2BBNi14wMKmwdpCDFMn1d71ra11GuQ4DORpHy-XXXXXXXXXXXXX'
	 , FileId='root:/folder/test_out.csv:'
	 --,FileId='01SUOJPKHXMPKD2UXXXXXXXXXXXXXXXXXX'  --by ID (preferred)
	 
	 )
--DriveId can be retrieved by selecting from 'Drives' table.
--FileId can be retrieved by selecting from 'list_files' endpoint.

Using OPENQUERY in SQL Server

SELECT * FROM OPENQUERY([LS_TO_SHAREPOINT_ONLINE_IN_GATEWAY], 'SELECT Data as BYTES_AS_BASE64_STRING, BASE64_TO_FILE(''C:\My files\Employees\List.xls'', Data) FILE_SAVED_TO_DISK_FROM_BASE64 
FROM download_file
WITH (
   -- Drive (SharePoint Document Library)
	  DriveId=''b!GtLN726LE0eY5F2BBNi14wMKmwdpCDFMn1d71ra11GuQ4DORpHy-XXXXXXXXXXXXX''
	 , FileId=''root:/folder/test_out.csv:''
	 --,FileId=''01SUOJPKHXMPKD2UXXXXXXXXXXXXXXXXXX''  --by ID (preferred)
	 
	 )
--DriveId can be retrieved by selecting from ''Drives'' table.
--FileId can be retrieved by selecting from ''list_files'' endpoint.')

Using EXEC in SQL Server (handling larger SQL text)

The major drawback of OPENQUERY is its inability to incorporate variables within SQL statements. This often leads to the use of cumbersome dynamic SQL (with numerous ticks and escape characters).

Fortunately, starting with SQL 2005 and onwards, you can utilize the EXEC (your_sql) AT [LS_TO_SHAREPOINT_ONLINE_IN_GATEWAY] syntax.

DECLARE @MyQuery NVARCHAR(MAX) = 'SELECT Data as BYTES_AS_BASE64_STRING, BASE64_TO_FILE(''C:\My files\Employees\List.xls'', Data) FILE_SAVED_TO_DISK_FROM_BASE64 
FROM download_file
WITH (
   -- Drive (SharePoint Document Library)
	  DriveId=''b!GtLN726LE0eY5F2BBNi14wMKmwdpCDFMn1d71ra11GuQ4DORpHy-XXXXXXXXXXXXX''
	 , FileId=''root:/folder/test_out.csv:''
	 --,FileId=''01SUOJPKHXMPKD2UXXXXXXXXXXXXXXXXXX''  --by ID (preferred)
	 
	 )
--DriveId can be retrieved by selecting from ''Drives'' table.
--FileId can be retrieved by selecting from ''list_files'' endpoint.'
EXEC (@MyQuery) AT [LS_TO_SHAREPOINT_ONLINE_IN_GATEWAY]