Hiding secret columns from users

Hi,
On my SQL Server 2000, I have a table of data (tblAllData) containing a
number of columns, some of which are 'secret'.
I have to let some users access the database using ODBC from an Excel
sheet, and I would like that they do not know at all that the columns exist.
I tried creating a view for them (qryAllData) that only selects the
columns that should be visible, but when the creating the
ODBC-connection, both the query and the underlying table shows up.
If I select the table as datasource, the query-builder in excel shows a
list of all the columns, including the secret ones. If I try selecting
then, of course, an error occurs.

I would like either that the columns for the table don't show or that
the table does not show at all - and only reveals the existence of the
view to the odbc-client.
Is that possible?

Here's what I tried so far:

USE DbAllData

sp_addlogin @loginame='ODBCAccess', @passwd='ODBCAccess', @defdb='DbAllData'

sp_grantdbaccess 'ODBCAccess'

sp_addrolemember  @rolename = db_denydatawriter, @membername = ODBCAccess



REVOKE ALL FROM ODBCAccess

DENY SELECT ON dbo.syscolumns TO ODBCAccess

DENY SELECT ON dbo.syscomments TO ODBCAccess

DENY SELECT ON dbo.sysdepends TO ODBCAccess

DENY SELECT ON dbo.sysfilegroups TO ODBCAccess

DENY SELECT ON dbo.sysfiles TO ODBCAccess

DENY SELECT ON dbo.sysfiles1 TO ODBCAccess

DENY SELECT ON dbo.sysforeignkeys TO ODBCAccess

DENY SELECT ON dbo.sysfulltextcatalogs TO ODBCAccess

DENY SELECT ON dbo.sysfulltextnotify TO ODBCAccess

DENY SELECT ON dbo.sysindexes TO ODBCAccess

DENY SELECT ON dbo.sysindexkeys TO ODBCAccess

DENY SELECT ON dbo.sysmembers TO ODBCAccess

DENY SELECT ON dbo.sysobjects TO ODBCAccess

DENY SELECT ON dbo.syspermissions TO ODBCAccess

DENY SELECT ON dbo.sysproperties TO ODBCAccess

DENY SELECT ON dbo.sysprotects TO ODBCAccess

DENY SELECT ON dbo.sysreferences TO ODBCAccess

DENY SELECT ON dbo.systypes TO ODBCAccess

DENY SELECT ON dbo.sysusers TO ODBCAccess

--allow selecting

GRANT SELECT (idx, col1, col2) ON tblAllData TO ODBCAccess

GRANT SELECT ON qryAllData TO ODBCAccess

Re: Hiding secret columns from users

You can specify WITH VIEW_METADATA so that only meta-data exposed by the
view is visible:

CREATE VIEW MyView
WITH VIEW_METADATA AS
SELECT MyPublicData FROM MyTable

--
Hope this helps.

Dan Guzman
SQL Server MVP

"Morten Mikkelsen" wrote in message
news:437e4f40$0$47014$edfadb0f@dread15.news.tele.dk...
> Hi,
> On my SQL Server 2000, I have a table of data (tblAllData) containing a
> number of columns, some of which are 'secret'.
> I have to let some users access the database using ODBC from an Excel
> sheet, and I would like that they do not know at all that the columns
> exist.
> I tried creating a view for them (qryAllData) that only selects the
> columns that should be visible, but when the creating the ODBC-connection,
> both the query and the underlying table shows up.
> If I select the table as datasource, the query-builder in excel shows a
> list of all the columns, including the secret ones. If I try selecting
> then, of course, an error occurs.
>
> I would like either that the columns for the table don't show or that the
> table does not show at all - and only reveals the existence of the view to
> the odbc-client.
> Is that possible?
>
> Here's what I tried so far:
>
>

> USE DbAllData

> sp_addlogin @loginame='ODBCAccess', @passwd='ODBCAccess', 

> @defdb='DbAllData'

> sp_grantdbaccess 'ODBCAccess'

> sp_addrolemember  @rolename = db_denydatawriter, @membername = ODBCAccess

>

> REVOKE ALL FROM ODBCAccess

> DENY SELECT ON dbo.syscolumns TO ODBCAccess

> DENY SELECT ON dbo.syscomments TO ODBCAccess

> DENY SELECT ON dbo.sysdepends TO ODBCAccess

> DENY SELECT ON dbo.sysfilegroups TO ODBCAccess

> DENY SELECT ON dbo.sysfiles TO ODBCAccess

> DENY SELECT ON dbo.sysfiles1 TO ODBCAccess

> DENY SELECT ON dbo.sysforeignkeys TO ODBCAccess

> DENY SELECT ON dbo.sysfulltextcatalogs TO ODBCAccess

> DENY SELECT ON dbo.sysfulltextnotify TO ODBCAccess

> DENY SELECT ON dbo.sysindexes TO ODBCAccess

> DENY SELECT ON dbo.sysindexkeys TO ODBCAccess

> DENY SELECT ON dbo.sysmembers TO ODBCAccess

> DENY SELECT ON dbo.sysobjects TO ODBCAccess

> DENY SELECT ON dbo.syspermissions TO ODBCAccess

> DENY SELECT ON dbo.sysproperties TO ODBCAccess

> DENY SELECT ON dbo.sysprotects TO ODBCAccess

> DENY SELECT ON dbo.sysreferences TO ODBCAccess

> DENY SELECT ON dbo.systypes TO ODBCAccess

> DENY SELECT ON dbo.sysusers TO ODBCAccess

> --allow selecting

> GRANT SELECT (idx, col1, col2) ON tblAllData TO ODBCAccess

> GRANT SELECT ON qryAllData TO ODBCAccess

> 

Re: Hiding secret columns from users

Dan Guzman wrote:

> You can specify WITH VIEW_METADATA so that only meta-data exposed by the
> view is visible:
>
> CREATE VIEW MyView
> WITH VIEW_METADATA AS
> SELECT MyPublicData FROM MyTable


This is a bit better.
However, now, when using excel to extract the data, the query designer
shows both MyView and MyTable in the dropdown for selecting the source.
If I select the table as source, the secret columns still show up.
How do I remove the table from the list of selectable choices while
still allowing them to select the data from it through the view?

TIA,
/M

Re: Hiding secret columns from users

Does the user have permissions on the table? In that case, the table will
be visible in the list.

--
Hope this helps.

Dan Guzman
SQL Server MVP

"Morten Mikkelsen" wrote in message
news:437fa8ec$0$47014$edfadb0f@dread15.news.tele.dk...
> Dan Guzman wrote:
>
>> You can specify WITH VIEW_METADATA so that only meta-data exposed by the
>> view is visible:
> >
>> CREATE VIEW MyView
>> WITH VIEW_METADATA AS
>> SELECT MyPublicData FROM MyTable
>
>
> This is a bit better.
> However, now, when using excel to extract the data, the query designer
> shows both MyView and MyTable in the dropdown for selecting the source.
> If I select the table as source, the secret columns still show up.
> How do I remove the table from the list of selectable choices while still
> allowing them to select the data from it through the view?
>
> TIA,
> /M
>

Re: Hiding secret columns from users

Dan Guzman wrote:
> Does the user have permissions on the table? In that case, the table will
> be visible in the list.

The user has to have select permissions on the table for the view to
work, right?


/M

Re: Hiding secret columns from users

> The user has to have select permissions on the table for the view to work,
> right?

No. Permissions on indirectly referenced objects are not checked as long as
the ownership chain is unbroken. The ownership chain is unbroken as long as
the objects involved are owned by the same user. This allows you to limit
user access to views and stored procedures while preventing direct access to
the underlying objects. Users only need permissions on those objects they
access directly. See the Books Online for more information on ownership
chains.

--
Hope this helps.

Dan Guzman
SQL Server MVP

"Morten Mikkelsen" wrote in message
news:43805880$0$47068$edfadb0f@dread15.news.tele.dk...
> Dan Guzman wrote:
>> Does the user have permissions on the table? In that case, the table
>> will be visible in the list.
>
> The user has to have select permissions on the table for the view to work,
> right?
>
>
> /M