I'm trying to connect to a linked server from .net core.
I connect to my SQL Server, but I cannot reach the Oracle Database linked on it.
For example, I can connect to an actual SQL Server Database with the cnnStr:
"Server=foo\SQLEXPRESS;Database=DatabaseName;Trusted_Connection=True;MultipleActiveResultSets=true"
But if I change the Database parameter to the linked server, I get an error "Cannot open database "dbLINK" requested by the login. The login failed"
Does anyone knows how to connect to a linked database?
Thanks in advance
I believe the right way to do that is either creating views that access your linked server or access your linked server data directly from your query, for example, SELECT * FROM OPENQUERY([LINKEDSERVERNAME], 'SELECT Id, Name, Age from USER');
It`s important to point out that views are probably gonna be a better practice in this case. If you change anything related to your linked server in the near future, you'll need to change things in only one place.
I am facing a strange issue. I have a linked server on ServerB for ServerA
Now, when I am calling a stored procedure from ServerB like
EXEC [ServerA].[Db].[dbo].[SpName] #Param1 #param2
I am getting error that
The EXECUTE permission was denied on the object 'SpName', database 'Db', schema 'dbo'.
But now when I am executing below query it is returning me result:
SELECT *
FROM [ServerA].[Db].[dbo].[tblName]
I don't know that why I am not able to execute stored procedure from ServerB. I am Db_Owner on both the server.
Screenshot of Linked server security
Linked server catalog
If a linked server query fails, the things to check are (in rough order of probability):
Try logging in locally on the linked server to test access directly. If you have no local access, obviously you won't have it through the link either.
Verify the correct credentials as used when accessing the linked server, and not another user you're not expecting. You can check this with EXEC ('SELECT USER_NAME(), SUSER_NAME()') AT [Server]; if the user name is not what you're expecting, check your linked server definition for the correct login mappings. If you can't access the server at all (any query fails), you have other problems (like Kerberos authentication issues if you're using integrated authentication).
Perform a sanity check that you're accessing the correct server with EXEC ('SELECT ##SERVERNAME') AT [Server]. The network name of a linked server can be changed using sp_setnetname, so the name you use to a access the server isn't necessarily the machine name.
If all else fails, dropping and recreating the linked server definition is always an option, but obviously this could disrupt production work.
I've performed multiple searches and read numerous pages and tried loads of different configurations and nothing seems to solve a nuisance problem we have. We have a SQL server (2008 R2 v10.50.4000) that has several linked servers to several different access databases on a different server. They are all set up using UNC paths and they work...for a time.
At some point, something happens and then we can no longer access the databases and the only way I have found to solve this is to restart the SQL server service, which obviously isn't ideal in a production environment. This is the exact error message we get when we try to access it:
OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "HIDDEN" returned message "The Microsoft Access database engine cannot open or write to the file '\servername\path01\path02\path03\databasename.mdb'. It is already opened exclusively by another user, or you need permission to view and write its data.".
Yet it works absolutely fine again if I restart the SQL Server service, so I know the settings are correct. I strongly suspect it has something to do with the Microsoft ACE driver because they all (the Access database linked servers) stop working at the same time - even though they all look at different files.
At this point I'm willing to try anything.
Can I use OPENDATASOURCE (or another mechanism) from a Stored Procedure to connect to the same database as a different user? If so, how?
The database is meant to be deployed to several customers, and replicated by them as many times as they want to, etc. For this reason, I CANNOT HARDCODE the database server's name or the database's name.
(I tried using OPENDATASOURCE, but it only accepts hardcoded connection strings.)
Might EXECUTE AS work in your situation? http://msdn.microsoft.com/en-us/library/ms181362.aspx
You can set up a Linked Server to connect to the remote server using the login's current security context (or other options as it applies to your situation).
From your stored procedure, you could access it with something like SELECT * FROM mylinkedservername.mylinkedserverdatabase.dbo.mytable
But you say you want to connect to the same database but using a different login? You're looking for impersonation. Perhaps you can do this making a Linked Server that references itself, I haven't tried it. Search Microsoft Help documentation for how to set it up normally and test if it does what you're looking to do.
We have a classic ASP application that simply works and we have been loathe to modify the code lest we invoke the wrath of some long-dead Greek gods.
We recently had the requirement to add a feature to an application. The feature implementation is really just a database operation requires minimal change to the UI.
I changed the UI and made the minor modification to submit a new data value to the sproc call (sproc1).
In sproc1 that is called directly from ASP, we added a new call to another sproc that happens to be located on another server, sproc2.
Somehow, this does not work via our ASP app, but works in SQL Management Studio.
Here's the technical details:
SQL 2005 on both database servers.
Sql Login is authenticating from the ASP application to SQL 2005 Server 1.
Linked server from Server 1 to Server 2 is working.
When executing sproc1 from SQL Management Studio - works fine. Even when credentialed as the same user our code uses (the application sql login).
sproc2 works when called independently of sproc1 from SQL Management Studio.
VBScript (ASP) captures an error which is emitted in the XML back to the client. Error number is 0, error description is blank. Both from the ADODB.Connection object and from whatever Err.Number/Err.Description yields in VBScript from the ASP side.
So without any errors, nor any reproducibility (i.e. through SQL Mgmt Studio) - does anyone know the issue?
Our current plan is to break down and dig into the code on the ASP side and make a completely separate call to Server 2.sproc2 directly from ASP rather than trying to piggy-back through sproc1.
Have you got set nocount on set in both stored procedures? I had a similar issue once and whilst I can't remember exactly how I solved it at the moment, I know that had something to do with it!
You could be suffering from the double-hop problem
The double-hop issue is when the ASP/X page tries to use resources that are located on a server that is different from the IIS server.
Windows NT Challenge/Response does not support double-hop impersonations (in that once passed to the IIS server, the same credentials cannot be passed to a back-end server for authentication).
You should verify the attempted second connection using SQL Profiler.
Note that with your manual testing you are not authenticating via IIS. It's only when you initiate the sql via the ASP/X page that this problem manifests.
More resources:
http://support.microsoft.com/kb/910449
http://support.microsoft.com/kb/891031
http://support.microsoft.com/kb/810572
I had a similar problem and I solved it by setting nocount on and removing print commands.
My first reaction is that this might not be an issue of calling cross-server, but one of calling a second proc from a first, and that this might be what's acting differently in the two different environments.
My first question is this: what happens if you remove the cross-server aspect from the equation? If you could set up a test system where your first proc calls your second proc, but the second proc is on the same server and/or in the same database, do you still get the same problem?
Along these same lines: In my experience, when the application and SSMS have gotten different results like that, it has often been an issue of the stored procedures' settings. It could be, as Luke says, NOCOUNT. I've had this sort of thing happen from extraneous PRINT statements in the code, although I seem to remember the PRINTed value becoming part of the error description (very counterintuitively).
If anything is returned in the Messages window when you run this in SSMS, find out where it is coming from and make it stop. I would have to look up the technical terms, but my recollection is that different querying environments have different sensitivities to "errors", and that a default connection via SSSM will not throw an error at certain times when an ADO connection from a scripting language will.
One final thought: in case it is an environment thing, try different settings on your ASP page's connection string. E.g., if you have an OLEDB connection, try ODBC. Try the native and non-native SQL Server drivers. Check out what connection string options your provider supports, and try any of them that seem like they might be worth trying.
Example code might help :) Are you trying to return two tables from the stored procedure; I don't think ADO 2.6 can handle multiple tables being returned.
I did consider that (double-hop), but what is the difference between a sproc-in-a-sproc call like I am referring to vs. a typical cross-server join via INNER JOIN? Both would be executed on Server1, using the Linked Server credentials, and authenticating to Server 2.
Can anyone confirm that calling a sproc cross-server is different than doing a join on data tables? And why?
If the Linked Server config is a sql account - is that considered a double-hop (since what you refer to is NTLM double-hops?)
In terms of whether multiple resultsets are coming back - no. Both Server1.Sproc1 and Server2.Sproc2 would be "ExecuteNonQuery()" in the .net world and return nothing (no resultsets and no return values).
Try to check the permissions to the database for the user specified in the connection string.
Use the same user name in the connection string to log in to the database while using sql mgmt studio.
create some temporary table to write the intermediate values and exceptions since it can be a effective way of debugging your application.
Can I just check: You made the addition of sproc2? Prior to that it was working fine for ages.
Could you not change where you call sproc2 from? Rather than calling it from inside sproc1, can you call it from the ASP? That way you control the authentication to SQL in the code, and don't have to rely on setting up any trusts or shared remote authentication on the servers.
How is your linked server set up? You generally have some options as to how it authenticates to the remote server, which include logging in as the currently logged in user or specifying a SQL login to always use. Have you tried setting it to always use a specific account? That should eliminate any possible permissions issues in calling the remote procedure...