Long story but I have a web app that has a SQL Server DB that works fine but also has a ASPNETDB.MDF database (for membership), which has always worked fine under SQL Server 2008. I did an upgrade on the server to SQL Server 2014 and I can no longer access the ASPNETDB.MDF database and get this error:
the server was not found or was not accessible. Verify that the
instance name is correct and that SQL Server is configured to allow
remote connections. (provider: SQL Network Interfaces, error: 26 -
Error Locating Server/Instance Specified)
I've modified the connection string to update to what is expected with 2014 and that works fine in a simple console app (I can connect, run SQL commands, etc.) But I have not been able to figure out why I can make it work in production. NOTE: it doesn't even work in a browser on the web server - I get the same error.
Here is my connection string:
<add name="DefaultConnection" connectionString="Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|ASPNETDB.MDF;Trusted_Connection=Yes" />
I think it's possible... but really, you'll do much better installing Sql Server Express Edition on that machine, and then attaching the mdf file to the Express instance.
You'll also need some work to setup security and a few other things, but this puts you back into a more "normal" or typical deployment scenario for a web database. This will also make it much easier to troubleshoot the kind of error seen in the question.
It maybe your Remote Connection is not enabled on Server Side.
You have to make sure that it is enabled.
Here's you some guide1 and guide2 to make it Done
Related
Lucky me, I got to work from home due to the COVID-19 outbreak. However, now when I try to use Visual Studio 2019 to run my app, NHibernate always fails from not finding my SQL Server instance.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
I then tried to connect to my test database through SQL Server Management Studio and it worked. I have no clue why one worked and the other didn't. I don't even know where to trouble shoot this issue, I know programming, but very little about setting up a server and networking. My guess is that it's something with me no longer being on our domain anymore, but why would this affect my local instance?
I tried letting SQL Server through the firewall, I checked to make sure remote connections are allowed. I also tried connecting with my local IP instead of with localhost, using just localhost, or even just (local) and none of that worked. I'm just completely lost otherwise.
Edit:
My connection string:
Data Source=localhost\SQLEXPRESS;Initial Catalog={0};Integrated Security=True;
How I connect via SQL Server Management Studio:
the following error appears when I want to launch the Security tab in ASP .NET Configuration site for my ASP NET MVC 4 project:
http://s14.postimg.org/jvizqragv/error_sql.png
I know that there are a lot of questions related to that error, but i tried a lot of the tips for solving this (I tried the suggested solutions here - http://blogs.msdn.com/b/walzenbach/archive/2010/04/14/how-to-enable-remote-connections-in-sql-server-2008.aspx but the error is still here).
But let me explain what are my databases in the solution. I have a local database (an .MDF file in App_Data) and a database for users authentication which was generated by ASP NET MVC. They are all placed in the App_Data folder as I'm trying to work on this solution on different machines. The strange thing is that on my laptop at home there is no such problem - I am able to create roles, explore users and all the functionality in the Security tab and I think there might be some problem with the SQL Server on my desktop machine - I use the Express edition on my laptop and the Developer edition on the other machine where things don't work.
My connection strings are the following:
<add name="FootballTransfers20130717145140Context" connectionString="Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\FootballTransfers.mdf;Integrated Security=True;MultipleActiveResultSets=True;Connect Timeout=30"
providerName="System.Data.SqlClient" />
<add name="DefaultConnection" connectionString="Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\DefaultConnection.mdf;Integrated Security=True;MultipleActiveResultSets=True;Connect Timeout=30"
providerName="System.Data.SqlClient" />
The first one is for the Entity framework and is related to the database where I store my application specific data. The second one is for the users administration database generated by SQL. Without the second connection string I'm not able to open any action of the Account controller.
It's very strange because it works on one machine and not on another. I was wondering if there's something wrong with the connection string, but I guess there's something with the SQL Server. As I said I tried various solutions but they didn't work.
LocalDB is a feature of SQL Server Express only. You will have to install SQL Server Express on the machine or import your database to your SQL Server and change your connection strings.
In production, you would probably have to move to a full SQL Server edition anyway.
I added the roles i was trying to make in code in the AccountController and now I'm able to register users with roles, but the problem that appeared now is that when I put the Authorize attribute on some action so that only users with certain roles can request them, the following error appears:
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
When I remove the attribute so anyone can access it, the action works fine. I found some article on the net saying that providers must be specified in the config, but some errors kept appearing that those tags are unknown.
I have checked the instance name, auto close is set to true, allow remote connections on the server is checked. The server is running when I open the SQL Server configuration manager. I have even rebooted. I have created this db the same way as all others. I use Entity Framework and have checked the names in the web.config and they match. This is the default connection string from the wizard - I use for testing before I deploy. I just can't think of anything else to check to figure out why it won't connect. Working inside SQL Server everything is fine.
Here is the general error.
A network-related or instance-specific error occurred while establishing a connection to SQL >Server. The server was not found or was not accessible. Verify that the instance name is >correct and that SQL Server is configured to allow remote connections. (provider: Shared >Memory Provider, error: 40 - Could not open a connection to SQL Server)
Config:
connectionString="metadata=res://*/Model.csdl|res://*/Model.ssdl|res://*/Model.msl;provider=System.Data.SqlClient;provider connection string='data source=.\SQL_1;attachdbfilename="C:\Program Files (x86)\Microsoft SQL Server\MSSQL10_50.SQL_1\MSSQL\DATA\A_db.mdf";integrated security=True;connect timeout=10;user instance=True;multipleactiveresultsets=True;App=EntityFramework'" providerName="System.Data.EntityClient" />
Thanks in advance.
Let me preface this answer by saying that proper setup of a SQL instance is not as easy as Microsoft would like you to think with the entity framework. It's a little bit involved and requires that you put your DBA hat on for a little bit.
The error you have indicates that the web instance is attempting to connect to the SQL server using Windows Integrated Security. This will work fine if (a) the windows user that the process is running as (which can be configured in IIS) is authorized to log on to the SQL server and has a valid login in the database and (b) if the SQL server is on the same machine or in the same domain as the IIS server.
In light of this, I recommend using SQL Server authentication. If you need to know how to do this, I recommend searching for "SQL Server Authentication setup" - here is an article that I found which might help you set this up.
http://msdn.microsoft.com/en-us/library/aa337562.aspx
In general, I recommend taking the following actions:
Connect to the sql server using MS SQL Management Studio.
Permanently attach your database, then use the Initial Catalog property on your connection string rather than AttachDbFileName
Then set up your login username and password on the SQL server, and create a login in the database for it.
Make sure your login can only execute the stored procedures you want it to execute. Deny it access to running sql statements.
You will also need to add the username and password to your connection string, and set IntegratedSecurity=false.
Let us know how things go once you get your SQL server set up properly.
This error means that your provider code cannot find the SQL Server. If you have checked the server instance name (it should be <yourLocalServer>\SQL_1), then it could be the attachdbfilename= parameter, as this is a really unreliable way to specify the database to connect to (you should be using the Database Name, not the file name), because there are about a hundred reasons that the file name could change that have nothing to do with your application.
After resolving issues with RIA installation here, I'm still getting this following error. Not much special - I tried to create a new screen based off of data sources from an existing database in a full SQL 2005 instance
An error occurred while establishing a
connection to SQL Server instance
'.\SQLEXPRESS'. A network-related or
instance-specific error occurred while
establishing a connection to SQL
Server. The server was not found or
was not accessible. Verify that the
instance name is correct and that SQL
Server is configured to allow remote
connections. (provider: SQL Network
Interfaces, error: 26 - Error Locating
Server/Instance Specified)
I've tried to correct the connection string in the, I guess, autogen'd config file. Even though Visual Studio doesn't seem to think that the file is overwritten on rebuild, the error continues to appear.
How can I use LightSwitch with full SQL 2005 rather than SQL Express?
It seems when working Locally, LightSwitch uses SQL Server Express. It puts it's Membership, Roles, and other authentication information here. I don't know any way to get around this locally, but when you go to "Publish" your project, you're given the ability to use a different database/server. You can also use whatever server/database you'd like for your data sources as well.
Hopefully, before V1, they'll allow you to change that. But I haven't found a way yet, without the config being overwritten constantly.
You can't use it with non Express version during development when you want to use LightSwitch to create your data model. If you deploy your project, as mentioned, you can use the created database with full version and change the connection string.
Although I would be cautious using SQL Server 2005 because LightSwitch is using datetime2 which is new in 2008. (maybe some more 2008 specifics as well)
http://lajak.wordpress.com/2011/10/04/lightswitch-change-default-database-instance/
Here, they are telling how to change instance name both in project level and global level.
Sorry if this is the most seen question on the web, but this is my turn. I am trying to publish my asp.net mvc app on IIS 7 under MS Sql Server 2008. I am on a Windows Server 2008 virtual machine. I get the following classical error:
A network-related or instance-specific
error occurred while establishing a
connection to SQL Server. The server
was not found or was not accessible.
Verify that the instance name is
correct and that SQL Server is
configured to allow remote
connections. (provider: SQL Network
Interfaces, error: 26 - Error Locating
Server/Instance Specified)
Under SQLServer, Allow remote connections is checked. My connection string is:
Data Source=.\MSSQLSERVER;Initial Catalog=mydbname;User Id=sa;Password=mypassword
I also tried with no username/password and "Integrated Security=true". There is only one instance of SQLServer installed.
I tried to access my web page locally and remotely. There is no active firewall on the virtual machine.
Make sure you have TCP/IP set up as a transport in your SQL Server configuration tool.
Thanks guys for the try. I found the solution and it is related to an info that I forgot to give. I hope it can help someone as new as me on these things.
I use NHibernate, and the connection string is actually in the nhibernate.cfg.xml file. The one in the web.config file is actually used by my various providers (users/roles). I fixed that by removing the connection string from the NH config file. I now retrieve it with:
string connectionString = ConfigurationManager.
ConnectionStrings["myConnectString"].ConnectionString;
and I set it in NH with:
Configuration cfg = new Configuration();
cfg.Configure(cfgFile);
cfg.SetProperty(NHibernate.Cfg.Environment.ConnectionString, connectionString);
Now I get:
Cannot open database "mydb"
requested by the login. The login
failed. Login failed for user 'NT
AUTHORITY\NETWORK SERVICE'.
But this is another story, for another question if I can't find the answer.
PS: I had to use "." as the server name otherwise .\MSSQLSERVER was producing a new error "invalid connection string". Thx Ian and Jared for the tip.
is that the actual data source line from the web config?
If so then it's should be in quotes of course, for safety add a ; on the end and check that is the actual name of your instance, you can check windows services for your instance name.
try substituting localhost instead of . and can you connect from sql server management studio using the credentials in your connection string?
As mentioned by Robert, try:
ConnectionString="Data Source=(LOCAL)\MSSQLSERVER;Initial Catalog=mydbname;User ID=sa;Password=mypassword"
I'm not sure if connection strings are case sensitve, but I notice that you have 'Id' instead of 'ID'.
Edit:
Am not sure if you need \MSSQLSERVER?
are you sure it's a named instance of SQL?
try
Data Source=.;Initial Catalog=mydbname;User Id=sa;Password=mypassword
UPDATE:
from this site
did you try the following:
Make sure the server machine is reachable, e.g, DNS can be resolve correctly, you are able to ping the server (not always true).
Make sure SQL Browser service is running on the server.
If firewall is enabled on the server, you need to put sqlbrowser.exe and/or UDP port 1434 into exception.
Well I am facing the same above issue since morning (past 8 hours) did lots of stuff like create a Domain Name, setup a new application pool identity but nothing worked :(
I just made a small changes in web.config file for connection string that is:
Integrated Security=False instead of True... and now it is working perfectly