Sp_oamethod to upload file with size greater than 8000 - sql

Question

This is part of my procedure to return #v_buffer variable.
Problem is that, the size of file i want to upload is greater than 8000 bytes. That's why i need to use varbinary(max) type.
But sp_oamethod read returns me an error.
Is someone know hot to use sp_oamethod to solve my problem?
declare #returnCode int
declare #v_file int
declare #v_buffer varbinary(max)
declare #v_fullpath nvarchar(400) --pdf file phusical location
exec #returncode = sp_oacreate 'adodb.stream', #v_file out
exec #returncode = sp_oamethod #v_file, 'open'
exec #returncode = sp_oasetproperty #v_file, 'type', 1
exec #returncode = sp_oasetproperty #v_file, 'loadfromfile', #v_fullpath
exec #returnCode = sp_oamethod #v_file, 'read', #v_buffer out, -1
if #returncode <> 0
begin
exec sp_oageterrorinfo #v_file
end
exec #returnCode = sp_OAMethod #v_file, 'Close'
exec #returnCode = sp_OADestroy #v_file
Error message returned by sp_oageterrorinfo:
0x8004271A, ODSOLE Extended Procedure, Error in srv_convert.

Answer 1

Please do not use the OLE Automation stored procedures (i.e. sp_OA* ) as they have been deprecated since SQL Server 2005 was released. What you are trying to do is rather simple with SQLCLR (i.e. .NET-based objects that exist within SQL Server). You can create a scalar function to accept a filepath and return its bytes using the File.ReadAllBytes method. Return that byte[] via the SqlBytes type.
You will need to set your Assembly to PERMISSION_SET = EXTERNAL_ACCESS. In order to accomplish that, please do not set the database to TRUSTWORTHY ON as that is an unnecessary security risk. Instead, sign the Assembly (using a password), then create an Asymmetric Key in the master Database from the DLL, then create a Login from that Key, and finally grant the Login the EXTERNAL ACCESS ASSEMBLY permission.
For a lot more information on working with SQLCLR, including many examples, please see the series of articles I am writing on this topic on SQL Server Central: Stairway to SQLCLR (that site does require free registration in order to read their content).
Or, if you don't want to deal with any coding, I created a library of over 270 functions and stored procedures called SQL#. There are several file system related functions, though none of them are available in the Free version. Still, the one that would help here is called: File_GetFileBinary.

Answer 2

If you try to pass a string that is greater than 4000 characters but less than or equal to 8000 characters in length to the sp_OASetProperty or to the sp_OAMethod OLE Automation extended stored procedure, the input string is silently truncated to 4000 characters before it is passed to the object and no error is returned.
If you try to set a property to a string that is greater than 8000 characters through the sp_OASetProperty OLE Automation extended stored procedure, or if you try to pass an input parameter to the sp_OAMethod OLE Automation extended stored procedure that is longer than 8000 characters, you receive the following error message:
hr Source Description
---------- ---------------------------- --------------------------
0x8004271A ODSOLE Extended Procedure Error in srv_convert.
https://support.microsoft.com/en-us/kb/325492

Answer 3

If someone had same problem, i have done it like this:
In my procedure i create temp #IMG table:
create table #IMG (FileID2 nvarchar(50), img image)
If the file size is greater than 8k, i split it to parts in size 8000 and update #IMG:
exec #returnCode = sp_oamethod #v_file, 'read', #v_buffer out, 8000
update #IMG set img = #v_buffer
SELECT #ptrval = TEXTPTR(Img) FROM #IMG WHERE FileID2 = #v_FileID2
--file split section
select #v_Blocks = #v_FileSize/8000+1
if #v_Blocks = 1
begin
WRITETEXT #IMG.Img #ptrval #v_buffer
end
else
begin
WRITETEXT #IMG.Img #ptrval #v_buffer
set #j=#v_blocks-1
while #j>0
begin
exec #returnCode = sp_oamethod #v_file, 'read', #v_buffer out , 8000
set #i=(select DATALENGTH(Img) from #IMG WHERE FileID2= #v_FileID2)
UPDATETEXT #IMG.Img #ptrval #i 0 #v_buffer
set #j=#j-1
end
end

Answer 4

You could use the same workaround as described at 0x8004271A ODSOLE Extended Procedure Error in srv_convert.
In your case, the line
exec #returnCode = sp_oamethod #v_file, 'read', #v_buffer out, -1
should be replaced by
Create table #tmp(dt varbinary(max))
insert into #tmp
exec #hr = sp_oamethod #v_file, 'read', #mode = -1
Select dt from #tmp -- single column/single row.
Drop Table #tmp -- clean up
Caution: this code wasn't tested. However the following code works fine for 32KB xml output:
Create table #tmp(dt xml)
insert into #tmp
exec #hr = sp_OAGetProperty #obj, 'responseXML.XML'
/*
Here is the trick: inserting from the returned result set, i.e.
`insert into <table>(<columns>) select <columns>`
*/
Select dt from #tmp -- single column/single row.
Drop Table #tmp -- clean up
responseXML.XML returns the whole xml document after calling MSXML2.ServerXMLHttp.send. The trick works according to section Result Sets of sp_OAMethod.
When the table variable type is available, the code can be even shorter:
DECLARE #xml(val xml);
insert into #xml
exec #hr = sp_OAGetProperty #obj, 'responseXML.XML'
Select * from #xml; -- just to see the output
I.e. there is no need to clean up.

Answer 5

I received the same issue. Apparently, you cannot use sp_OAMethod with a VARBINARY(MAX) variable.
Try changing: declare #v_buffer varbinary(max)
to declare #v_buffer varbinary(8000).
Good luck!