A while ago, I wrote a web-based guestbook application that wrote it's own database.
My code was very amateurish, but, as it was my very first publication, I was very happy with it.
Only about a month after I'd published it did I realize I'd made a huge mistake in the code.
I've only ever connected to a specific named instance of SQL Server, and it occurred to me that, if the SQL Server instance has a different name than the one I specified, it wouldn't work.
So, since my users will probably not know what the name of the instance of SQL Server that's running is, I thought adding a field where the user can specify it would help if they do, but what if they don't?
My answer was to get the local instance, regardless of name.
I tried Data Source=.\local;, Data Source=.; and other variants, but nothing worked.
Any ideas?
A non-named instance is called "default instance" and can be accessed using "Data Source=(local);...".
The only way of knowing which instances are running is by querying the SQL Browser Service, if it's running.
I guess most of your users are running SQL Server Express? If so, the service is called local\SQLEXPRESS. If not, it's local or they've named it themselves. So, I would try local\SQLEXPRESS first, then local. If none works, just throw an exception and ask the user to add it themselves.
Related
I followed a tutorial on the internet to create my own database. I succesfully built a program upon it. Then I created an access .mdb file(another database) and then I just changed the database which the program connected to, to the one which I created.
I just made that one change. But then it started showing me error whenever I tried to update using
da.update(ds,"Phone Book")
where da is data adapter and ds is data set.
The error was: " syntax error in INSERT INTO statement"
I have just changed the DB that the program is connecting to. I did not change the code one bit.
EDIT: I forgot to mention, I searched for this on google, and one thing which I read was, that access database might be only read only or something. But I unchecked the read only box, so I don't know whether it still might be the problem. Although, I don't think there is a problem with the code
EDIT: I just discovered now, that even if I change the table which is being referred to, it throws up the same error.
It sounds like the first database probably used something like Sql Server Express. That's a completely different kind of database then Access, with a different providers, different dialect of SQL, connection string, etc. Why would you think you can change all that without breaking some of your code?
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.
Every SQL Server connection string I ever see looks something like this:
Data Source=MyLocalSqlServerInstance;Initial Catalog=My Nifty Database;
Integrated Security=SSPI;
Do I need the Initial Catalog setting? (Apparently not, since the app I'm working on appears to work without it.)
Well, then, what's it for?
If the user name that is in the connection string has access to more then one database you have to specify the database you want the connection string to connect to. If your user has only one database available then you are correct that it doesn't matter. But it is good practice to put this in your connection string.
This is the initial database of the data source when you connect.
Edited for clarity:
If you have multiple databases in your SQL Server instance and you don't want to use the default database, you need some way to specify which one you are going to use.
Setting an Initial Catalog allows you to set the database that queries run on that connection will use by default. If you do not set this for a connection to a server in which multiple databases are present, in many cases you will be required to have a USE statement in every query in order to explicitly declare which database you are trying to run the query on. The Initial Catalog setting is a good way of explicitly declaring a default database.
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...
I need to convert a named instance of SQL server 2005, to a default instance.
Is there a way to do this without a reinstall?
The problem is, 2 out of 6 of the developers, installed with a named instance. So its becoming a pain changing connection strings for the other 4 of us. I am looking for the path of least resistance to getting these 2 back on to our teams standard setup.
Each has expressed that this is going to be, too much trouble and that it will take away from their development time. I assumed that it would take some time to resolve, in the best interest of all involved, I tried combing through configuration apps installed and didn't see anything, so I figured someone with more knowledge of the inner workings would be here.
I also wanted to convert a named instance to default - my reason was to access it with just the machine name from various applications.
If you want to access a named instance from any connection string without using the instance name, and using only the server name and/or IP address, then you can do the following:
Open SQL Server Configuration Manager
Click SQL Server Network Configuration
Click Protocols for INSTANCENAME you want to make available (i.e. SQLExpress)
Right-click TCP/IP and click Enabled
Right-click TCP/IP and go to Properties
Go to the IP Addresses tab
Scroll down to the IPAll section
Clear the field TCP Dynamic Ports (i.e. empty/blank)
Set TCP Port to 1433
Click Ok
Go to SQL Server Services
Right-click your SQL Server (INSTANCENAME) and click Restart
This will make the named instance listen on the default port. Note : You can have only one instance configured like this - no two instances can have same port on the IP All section unless the instance is a failover cluster.
As far as I know, no. One reason is the folder structure on the hard drive; they will have a name like MSSQL10.[instancename]
This is why a lot of companies store their applications' connection strings at the machine level instead of the application level.
Just take the connection string out of the source code entirely. Then have everyone put their connection string in their machine.config.
This has the added benefit of avoiding unnecessary app-specific environment logic, i.e. when you copy your application to the staging server, the staging server already "knows" what database to use.
The only way to change the instance name is to re-install - uninstall and install as default instance.
A lot of times I'll use client alias to point an application at a different sql server than the ones it's connection string is for, esp. handy when working on DTS or an application with a hard coded connection string. Have everybody use a commonly named alias, use the alias in the connection string and point the alias’s on each dev box to the to the different instances. That way you won't have to worry about if the server is the default instance or not.
You shouldn't ever really need to do this. Most software that claims to require the default instance (like Great Plains or Dynamics) doesn't actually.
If you repost with your situation (installed X, then Y, but need to accomplish Z) I bet you'll get some good workarounds.
I think you can migrate your data from Sql Server without having default instance installed. You can just specify the port number of your Sql Server instance in Oracle Sql Developer and you can connect just using the server name, not using the server name and the instance.
Like this:
connect to "MYSERVER, 1433"