I've got an C# .Net 3.5 executable that runs on a local machine and makes database calls to a server running SQL Server 2005. I've added a System DSN using the Data Sources manager on the local machine called "localserver" (with the driver set to SQL Server). When I create the DSN, I can test the connection to the server successfully.
I've added localserver to my connection string in my executable, and I get an 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: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)"
The server I am connecting to does allow for remote connections. When I replace localserver with the server name, it connects fine, but this program will be at multiple locations with multiple server names, so I need to make the data source dynamic.
Any ideas as to why this is happening?
Thank you,
Aaron
EDIT:
I've also tried using "localserver,1433" as my data source, but I get this 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: TCP Provider, error: 0 - No such host is known.)"
EDIT:
Thank you for your responses. To solve my problem, I made a small method to gather the servername using an odbc connection.
I can then send the servername to the SqlConnection. Thanks again for your input.
SqlClient (ie. SqlConnection) has absolutely nothing to do with ODBC. As such using an ODBC Data source Name in the SqlClient connection string will get you nowhere fast.
You can configure the server name in app.config and build the connection string using SqlConnectionStringBuilder. At deployment, you change the exe's or the user's .config file appropriately.
As Remus said, DSN has nothing to do with SqlConnection. Instead use this connection string:
http://www.connectionstrings.com/sql-server-2005#1
Also read this:
http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring.aspx
An Excerpt from the above post:
To connect to a local computer,
specify "(local)" for the server. If a
server name is not specified, a
connection will be attempted to the
default instance on the local
computer.
I would repeat that SqlConnection has nothing to do with DSN,
Related
I've built an .asmx web service which retrieves informations from a local sql server 2014 database.
Everything is working fine on localhost, but after publishing the web service to Azure i get the error:
An unhandled exception of type 'System.Web.Services.Protocols.SoapException'
occurred in System.Web.Services.dll
Additional information: Server was unable to process request. ---> 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)
SQL Server is configured to allow remote connections.
My connection string is like:
string con2 = #"Data Source=OfficePc\MSSQLSERVER2014;Initial Catalog=Database;Persist Security Info=True;User ID=Admin;Password=123456";
Is the error the result of something missing from the connection string, or am i missing some configurations changes?
As Paul mentioned in a comment under the question, your connection string is pointing to a local database resource (presumably on your dev machine). Even though you configured your local database server to support remote connections, the address OfficePc\MSSQLSERVER2014 isn't addressable, as that does not equate to a machine address (IP address).
Your app would need to connect to your database via an accessible IP address (which might require you to do some port-forwarding on your local network, or open ports on your firewall).
Alternatively, you can migrate your database to Azure (either with SQL Server in a VM or with the SQL Database service).
Keep in mind: If you are accessing a local (on-premises) database server from Azure, there will be latency added, as well as some outbound bandwidth costs.
It looks like SQL Server instance is not running or not accessible. Try connecting to the same database using SSMS and if you get the same error then the instance is not running.
Mostly the error occurs when the Database server was not found. Recheck if the server name (Data Source) is mentioned correctly. If you manually generated the connection string use .uld file to generate connection string.
To auto generate connection string using .udl file:
Create a sampe.txt file.
Rename it as sample.udl file.
Then double click on it, It will show you window entitled 'Data Link Properties'.
Configure the connection there.
Then Test the connection using test connection button.
Then open the file with notepad. It will show you the exact connection string.
For further reference check : MSDN
I need to access database in another computer using c#...I am using connection string with IP address for accessing database and also changed firewall setting but it shows error as follows
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: TCP
Provider, error: 0 - A connection attempt failed because the connected
party did not properly respond after a period of time, or established
connection failed because connected host has failed to respond.)
I m using this connection string
SqlConnection con = new SqlConnection("data source=192.168.1.12,1063;initial catalog=trinity;integrated security=false;network library=DBMSSOCN");
This is actually quite a large topic involving: Networking, Authentication, Authorization and Permissions. Quick checklist:
Open port 1433 on local firewall where SQL Server is running.
Open SQL Server Configuration Manager on the local machine where SQL Server is running and enable TCP connections.
Add a Windows Login or SQL Account user and grant permissions to the database. DON'T USE THE SA ACCOUNT TO CONNECT REMOTELY EVER!.
In your connection string you have Integrated security=false;, so you need to provide User ID=mysqlserveruserid;Password=mysqlserverpassword; parameters in your connection string instead. If you change Integrated security=true; your Windows credentials will be used.
Also why the IP Address? Do you not have network name resolution on your network? e.g. DNS or WINS.
Is SQL Server running as the default instance or does it have a named instance? If it's a named instance (would have been a choice taken when installing SQL Server) You will need Data source=computername\sqlserverinstancename;
More detailed information on all these aspects can be found on MSDN
https://msdn.microsoft.com/en-us/library/ms345332.aspx
Try given solutions, it may help you
http://blogs.msdn.com/b/walzenbach/archive/2010/04/14/how-to-enable-remote-connections-in-sql-server-2008.aspx
I cannot connect to a particular SQL Server 2008 database server from C#.
I am able to connect using SSMS, and run queries using SQLCMD, but when I try to connect from C# using the SqlConnection it fails to open the connection with a SqlException:
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)
Here is my code:
using (SqlConnection conn = new SqlConnection(#"Server=LDNPSM050000137\PLN000000014T;Initial Catalog=MiscData;Integrated Security=True;"))
{
//exception occurs on this line
conn.Open();
//use connection
conn.Close();
}
I get a similar response using ODBC:
string connectionString = #"Driver={SQL Server Native Client 10.0};Server=LDNPSM050000137\PLN000000014T;Database=MiscData;Trusted_Connection=yes;";
using (OdbcConnection connection = new OdbcConnection(connectionString))
{
connection.Open();
}
This fails with an OdbcExcpetion:
ERROR [08001] [Microsoft][SQL Server Native Client 10.0]SQL Server Network Interfaces: Error Locating Server/Instance Specified [xFFFFFFFF].
ERROR [HYT00] [Microsoft][SQL Server Native Client 10.0]Login timeout expired
ERROR [08001] [Microsoft][SQL Server Native Client 10.0]A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online.
I have checked the server and instance name are correct, and the server is configured to allow remote connections because I can connect through SSMS. Does anybody have a suggestion of what the problem could be or how to resolve this?
Update:
In case this helps somebody diagnose the problem - This is specific to my machine/user account. My colleague can run the code fine from his machine. I am also able to connect to my local instance using a connectionstring with the appropriate changes to the Server and Initial Catalog.
The error occurs for all remote database servers.
I'm not sure if this is specific to my company's specific IT infrastructure - but the reason this was not working for me was because the project was saved in My Documents which stored on a network share. Apparently .NET will not let you connect to a remote database server when the executing code is located on a network share - it work fine when I copied the project to my local drive. I am using Windows 7 and Visual Studio 2012.
Network shares by default have partial trust, so things that work when a project is on your local drive, e.g. connecting to remote server, won't from network location.
You can give the network location full trust (https://msdn.microsoft.com/en-us/library/zdc263t0(VS.80).aspx) or move your project onto your local drive.
I think the problem is the Server value in your Connect string:
From MSDN
I think you need to do this:
Server=tcp:LDNPSM050000137\PLN000000014T
Server=np:LDNPSM050000137\PLN000000014T
Depending upon whether you want to use TCP or Named Pipes...
I have a database called Library created in SQL Server 2014 under my locally created server instance. I am using that database as the datasource in my windows form application. It is working perfectly when on my computer, but when I run it on other machines, it stops with the error
Unhandled exception occurred...
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: Named
Pipes Provider, error: 40 - could not open connection to SQL Server)
I have started all services from configuration manager and have enabled tcp/ip under protocols for MSSQLSERVER. Is there any way I can accomplish this, or do I have to shift to local db?
Make sure that your connection string includes your remote machine name as part of the "Data Source", so something like :
connectionString="Data Source=machinename\SQLExpress;Initial Catalog=mydbname;Integrated Security=True"
note that this connection string will target a db name "mydbname", under the machine machinename which has a SQL Express instance.
if that didn't work let me see your connection string.
I am using VSTS 2008 + .Net 3.5 + C# + SQL Server 2008 Enterprise on Windows Server 2003. I am using the following connection string, and labtest1 is the local machine name and I connect from local machine using ADO.Net. Then it always fail with connection error. But when I change in the connection string from "labtest1" to ".", connection has no issue with the same ADO.Net client code. Any ideas what is wrong?
Data Source=labtest1;Initial Catalog=CustomerDB;Trusted_Connection=true;Asynchronous Processing=true
Here is the detailed error message I got,
System.Data.SqlClient.SqlException: 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: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
Looks like a Sql Server configuration issue to me : have you tried to tune protocols in Sql Server Network configuration ? Named Pipes or TCP/IP should be enabled.
When you use "." or "(local)" it connects to the default instance on your PC, perhaps the SQL Server was installed with instances, in which case you have to specify the instance name in the connection string in the format "SERVER\INSTANCE_NAME".
In SQL Management studio execute this query to see your full server\instance name
select ##servername
I have seen this issue previously with ZoneAlarms blocking the connection (on the machine trying to connect to the SQL server). I would spend some time investigating this area around firewalls etc.
Hope this helps
Do you have the Named Pipes network protocol enabled in the network config? (In the SQL Server Configuration Manager - sql server 2005, that's what I have, might be different in 2008 - you should be able to verify this setting)
Try to ping by the computer name: ping labtest1. if it does not find the server, then try ping labtest1.mydomainname.com with the domain name. If this works, then you just need to add/fix the DSN aliases in the domain controller or just re-login to the machine.
One other thins - and may not be relevant - but you've not specified the security model, at least not in the string provided as a sample.
I would expect to see: Integrated Security=True (given that its the local machine) in the connection string.
The other thing that may be relevant is - as has already been mentioned - the protocols, I'd look to make sure that TCP/IP is enabled.