bulk insert works in ssms but not in other applications - sql

Question

Context: SQL Server 2005
I have a simple proc, which does a bulk load from an external file.
ALTER proc [dbo].[usp_test]
AS
IF OBJECT_ID('tempdb..#promo') is not null BEGIN
DROP TABLE #promo
END
CREATE TABLE #promo (promo VARCHAR(1000))
BULK INSERT #promo
FROM '\\server\c$\file.txt'
WITH
(
--FIELDTERMINATOR = '',
ROWTERMINATOR = '\n'
)
select * from #promo
I can run it in SSMS. But when I call it from another application (Reporting service 2005), it throws this error:
Cannot bulk load because the file "\server\c$\file.txt" could not be opened. Operating system error code 5 (Access is denied.).
Here is complicated because it may related to the account used by reporting service, or some windows security issue.
But I think I can maybe impersonate the login as the one I used to create the proc because the login can run it in SSMS. So tried to change the proc to 'with execute as self', it compiles ok, but when I tried to run it in SSMS, I got:
Msg 4834, Level 16, State 4, Procedure usp_test, Line 12
You do not have permission to use the bulk load statement.
I am still in the same session, so when I run this, it actually execute as the 'self', which is the login I am using now, so why I got this error? What should I do?
I know it's bit unclear so just list the facts.
========update
I just tried using SSIS to load the file into a table so that the report can use. The package runs ok in BIDS but when runs in sql agent job it got the same access to the file is denied error. Then I set up a proxy and let the package run under that account and the job runs no problem.
So I am thinking is it the account ssrs used can't access the file? What account is used by ssrs? Can ssrs be set up to run under a proxy like sql agent does?
==============update again
Finally got it sorted
I have created a SSIS package, put the package in a job (running under a proxy account to access the file), and in the proc to execute the job. This does work although tricky (need to judge whether the job has finished in the proc). This is too tricky to maintain, so just create as a proof of concept, will not go into production.
http://social.msdn.microsoft.com/Forums/sqlserver/en-US/761b3c62-c636-407d-99b5-5928e42f3cd8/execute-as-problem?forum=transactsql

Answer 1

1) The reason you get the "You do not have permission to use the bulk load statement." is because (naturally) you don't have permissions to use the bulk load statement.
You must either be a sysadmin or a bulkadmin at the server level to run BULK commands.
2) Yes, "Access is denied" usually means whatever credentials you are using to run the sproc in SSRS does not have permissions to that file. So either:
Make the file available to everyone.
Set a known credential with full access to the file to the datasource running the sproc.
3) What the heck, dude.
Why not just use the text file directly as a data source in SSRS?
If that's not possible, why not perform all your ETL in one sproc run outside SSRS, and then just use a simple "select * from table" statement for SSRS?
Please do not run a BULK INSERT every time someone wants the report. If they need up to date reads of the file, use the file as a data source. If they can accept, say, a 10 minute lag in data, create a batch job or ETL process to pick the file up and put it into a database table every 10 minutes and just read from that. Write once, read many.