Question

Modifiable SQL Function using WITH EXECUTE AS...

Asked by: kalliopi

Hi,

Is there ANY way to create an inline table function that impersonates someone else?


More Details:
Specifically, I want to create a table "TableA" that a user does NOT have permission to see/modify in any way.  Then, I want to create a function called FunctionA along the lines of this:

CREATE FUNCTION FunctionA()
RETURNS TABLE
WITH EXECUTE AS N'dbo'
AS
     RETURN (SELECT * FROM TableA where TableA.UserName = user_name())
GO

This would create a function that I could use JUST like a table, but which would only let me see/modify/delete the records that were associated with MY username.  All other data would be filtered out by the function and since my username would NOT have access to the table directly - I would have secure access to my data only.  Does that make any sense?

Anyway - I've been going around and around with INLINE TABLE functions (which don't seem to allow WITH EXECUTE AS) and MULTILINE table functions which don't seem to allow INSERT INTO in the way that INLINE TABLE functions do.

Any suggestions?

Thanks.

EJ

This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.

Subscribe now for full access to Experts Exchange and get

Instant Access to this Solution

  • Plus...
  • 30 Day FREE access, no risk, no obligation
  • Collaborate with the world's top tech experts
  • Unlimited access to our exclusive solution database
  • Never be left without tech help again

Subscribe Now

Asked On
2008-06-30 at 13:46:25ID23528323
Tags

SQL

,

Function

,

Transact SQL

,

SQL Server

,

INTLINE

,

MULTILINE

,

RETURNS

,

EXECUTE AS

Topics

SQL Server 2005

,

MS SQL Server

,

SQL Server 2008

Participating Experts
1
Points
500
Comments
6

Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.

  • "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
  • "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
  • "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.

See what Experts Exchange can do for you.

Got a question?

We've got the answer.

Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.

Screenshot of Experts Exchange Knowledgebase

Need individual assistance?

Our experts are ready to help.

If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.

Screenshot of Experts Exchange Knowledgebase

Want to learn from the best?

Read articles from industry experts.

Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.

Screenshot of an Article

Working on a long term project?

Store your work and research.

Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.

Screenshot of Experts Exchange Knowledgebase

Access the answers to your technology questions today.

Subscribe Now

30-day free trial. Register in 60 seconds.

What Makes Experts Exchange Unique?

Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Trusted by the world's most respected brands.

image of each brand's logo

Faithfully serving IT professionals since 1996.

Experts Exchange Logo

Try it out and discover for yourself.

Subscribe Now

30-day free trial. Register in 60 seconds.

Related Solutions

  1. Impersonation Guide!!!
    hi, our company was using a Client-Server System(VB & SQL)the Authentication,Roles and User rights are all implemented at the back end,then we migrate to N-Tier Application. For Phase1 the security at the Back-End will stay as it's(at SQL Data Base). For Phase2 we will ma...
  2. impersonation issue
    i have a client and we are not able to get the app installed over at his location. A location where I am not at right now so I am trying to help them by email. I have this working on my app and they have run the necessary commands to set this up. The only thing I can think o...
  3. Code Inline SQL
    What does it mean when asked "Is all code inline sql in your application?" I am building a VB.NET application that stores into MS Access, and has not queries.
  4. Impersonate a User, then run SQL commands
    Using SQL Server 2000 and Visual Basic Net 2005. SQL Server is using Windows Authentication. Server OS is Windows 2003 Standard Edition Users are mostly Windows XP, may be some on Windows 2000. I've set up a user, SQL_Reports. I want some users who do not have SQL Server ri...
  5. impersonation and forms authentication
    I am using forms authentication for my application and i want to use impersonation for displaying a pdf file which is located in a remote directory. The impersonated user has permission to read that remote folder. We are using IIS6.0, however we have selected the option run ...

Free Tech Articles

  1. WARNING: 5 Reasons why you should NEVER fix a computer for free.
    It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
  2. SCCM OSD Basic troubleshooting
    SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
  3. Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
    This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
  4. Create a Win7 Gadget
    This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
  5. Outlook continually prompting for username and password
    There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
  6. Backup Exchange 2010 Information Store using Windows Backup
    There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...

Cloud Class Webinars

  1. Avoiding Bugs in Microsoft Access
    Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
  2. Top 10 Best New Features in Visio 2010
    Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
  3. IT Consultant Business Secrets Revealed
    Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
  4. Disaster Recovery and Business Continuity
    Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
  5. Organize Your Visio Diagrams with Containers and Lists
    Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
  6. How to Us Objects, Properties, Events and Methods in Microsoft Access
    Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...

Join the Community

Give a Little. Get a Lot.

Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.

Join the Community

Answers

 

by: angelIIIPosted on 2008-06-30 at 13:49:55ID: 21902923

actually, a VIEW would do just the same.

CREATE VIEW MyTableData
AS
  SELECT a.* 
    FROM dbo.TableA a
   WHERE a.UserName = user_name())

                                              
1:
2:
3:
4:
5:

Select allOpen in new window

 

by: angelIIIPosted on 2008-06-30 at 13:51:18ID: 21902934

anyhow, for the function:

CREATE FUNCTION dbo.FunctionA()
RETURNS TABLE
-- WITH EXECUTE AS N'dbo'  -- this defaults to the function owner (ie dbo)
AS
     RETURN (SELECT * FROM dbo.TableA a where a.UserName = user_name())
                                              
1:
2:
3:
4:
5:

Select allOpen in new window

 

by: kalliopiPosted on 2008-06-30 at 14:30:00ID: 21903169

Yeah - that's what I've been playing with.  If I run the following insert statement on FunctionA and I have permission to insert into the underlying table - then everything works great.  What I'm trying to create is a Function (or view) that I can insert into as below, where I _DON'T_ have access to the underlying table, but am still able to insert data into the view or function by controlling permissions on THAT object instead.  Does that make sense?

INSERT INTO dbo.FunctionA() (field1) values ('value1');

                                              
1:

Select allOpen in new window

 

by: angelIIIPosted on 2008-06-30 at 21:33:16ID: 21904998

you cannot INSERT into a function.
in which case, you need to use the view instead.

which still allows you to specify the permissions:
grant the SELECT, INSERT on the view, and deny SELECT, INSERT on the table.

 

by: kalliopiPosted on 2008-07-01 at 07:23:05ID: 21908101

I CAN insert into a function - I've done it.   You can (at least in 2005) insert into an inline table function.  I have the following function and I can insert into it:

CREATE FUNCTION [Test] ()
RETURNS TABLE
AS
      RETURN SELECT ID FROM foo WHERE username = user_name();
GO

I suppose from SQL Server's point of view (no pun intended :), this basically is a view - but since it's a function I can pass parameters into it - and I can use it like a regular table, selecting, inserting and deleting from it...

That being said, if I deny select/insert on the table, but allow it on the view, that works?  I'll be able to insert into the view, but not into the table?  That's fantastic.  I'll give that a try - thanks.

EJ

 

by: kalliopiPosted on 2008-07-01 at 07:46:41ID: 31472158

Thanks angelIII - your suggestion to grant permission the view, but NOT on the table works PERFECTLY.   Thank you - that's EXACTLY what I needed - thanks.

EJ

20120131-EE-VQP-002

3 Ways to Join

30-Day Free Trial

The Experts

98% positive feedback on 31,087 answers since March 2000. angeliii is a Microsoft Most Valuable Professional for his work with MS SQL Server & Develoment.

He has also proven his knowledge of Visual Basic Programming, PHP Scripting and Oracle Databases.

The Experts

97% positive feedback on 10,752 answers since July 2000. lrmoore has more than 18 years experience in the networking industry.

The six-time Mircosoft MVPs specialties include firewalls, virtual private networking, and network management.

Testimonials

"...and excellent source for support... Kind of like having your very own IT dept." Electriciansnet

Testimonials

"I was apprehensive at signing up at first. However... it has already made my life as an IT administrator much easier." JaCrews

Testimonials

"WOW! You guys have great, active, and knowledgeable people on here." moore50

Business Clients

Business Clients

In the Press

"If you’ve got a question... Experts Exchange can supply an answer.”

In the Press

"...an invaluable aid for both IT professionals and those who require tech support."

In the Press

"where IT professionals provide quick answers on just about any topic"

Business Account Plans

Loading Advertisement...