connecting database to server probably [duplicate] - c#

This question already has answers here:
Cannot Connect to Server - A network-related or instance-specific error
(54 answers)
Closed 3 years ago.
I tried making a site for a school project and when I go ahead and input values in the labels in the register page and send it starts loading for some time and then opens up the code in the server side:
SqlConnection conn = ConnectToDb(fileName);
in this line -----> conn.Open();
and this error msg appears:
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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)'

You should check your connection string and that you have enough permissions to connect to that database

This is likely because (1) you have the wrong connection string (Example: Wrong server name), or (2) you're loading the connection string from a missing/invalid configuration file. For example, if you're running in debug mode and you your application is trying to load *.debug.config file.
There are other reasons, like you are using NT Authentication and the identity your application is running under does not have SQL Server access.

Related

Server error in '/' Application .asp webforms

I've added to my .asp website a CreateUserWizard with destination page url home. After I'm launching it in Visual Studio 2013, it opens, I register, but, after a long delay after pressing sign up, it shows me 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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
Should I create a database myself or how it can't locate the server?
I think that connection string for database is not correct. Try creating an empty database and add that connection string in web config.
The error is telling you it can't find the database you have specified in your connection string (perhaps a typo or an incorrect details)
this page will help you create the connection string. You will just need your server details

SQLException cannot connect in ASP.NET MVC [duplicate]

This question already has answers here:
Cannot Connect to Server - A network-related or instance-specific error
(54 answers)
Why did a network-related or instance-specific error occur while establishing a connection to SQL Server?
(15 answers)
A network-related or instance-specific error occurred while establishing a connection to SQL Server [closed]
(1 answer)
update-database: "A network-related or instance-specific error occurred while establishing a connection to SQL Server"
(5 answers)
Closed 5 years ago.
I have moved a project that used to work fine but now it cannot acces my database anymore. I use Entity Framework and have connected to the database in SQL Server 2012 successfully. Here is what my connection string looks like :
<connectionStrings>
<add name="PrincipalServerContext"
connectionString="Data Source=ServerName\SQLEXPRESS;Initial Catalog=PrincipalServerDB;Integrated Security=True"
providerName="System.Data.SqlClient"/>
</connectionStrings>
When I launch the website, after authentication I retrieve data, but it throws the exception
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)
at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
I believe it might have to do with several things but am not sure, and don't know how to fix them :
User permissions in SQL Server
Connection strings could be wrong but I checked and re checked a hundred times
Could not make it work like this, and the exception is throw on Linq queries to access DB.
EDIT I did try to publish the web site to test, and have a second connection string :
<connectionStrings>
<add name="PrincipalServerContext_DatabasePublish"
connectionString="Data Source=ServerName\SQLEXPRESS;Initial Catalog=PrincipalServerDB;Integrated Security=True"
providerName="System.Data.SqlClient"/>
</connectionStrings>
Though I'm just trying to debug on the new computer I set up the project, if I remove this line, I have an exception. So maybe my program is searching for this DB and finds nothing?
System.InvalidOperationException cannot find PrincipalServerContext_DatabasePublish connection string
(I translate from french)
It likely isn't related to user permission. Rather, the new server you moved the project to cannot access the server SQL Server is located on.
If the new server has telnet, try this in Command Prompt on the Application Server:
telnet serverName 1433
it'll likely hang there trying to connect. Few things you could do:
Make sure there is no firewall blockage between the two servers if they are on different zones.
Check if SQL Server's Server has an inbound rule open for port 1433 (SQL Server Express doesn't open this port by default, but Enterprise and Standard do).
Check to see SQL Server is accepting TCP IP and Named Pipe connections through Sql Server Configuration Manager.

error: 40 - Could not open a connection to SQL Server [duplicate]

This question already has answers here:
Provider named pipes provider error 40 could not open a connection to SQL Server error 2 [duplicate]
(9 answers)
Closed 3 years ago.
Hi I'm writing a simple console application to save XML data into the database using bulkcopy but am currently having problems connecting to my database.
I am getting a SqlException 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)
I have checked for issues ensuring my SQL server is running and that it's configured correctly. Below is my connection string.
string connectionString = #"Data Source=SYAZANA;Initial Catalog=WangSCM;integrated security=true;" ;
I'm at my wits ends trying to figure out the error, what is the mistake that I'm making?
Follow the steps:
*Go to SQL Server Configuration manager
*SQL Server Network Configuration:
*Protocol for MSSQLSERVER
*In the right pane split page you will have to disable VIA as follows
--->Shared Memory - Enable
--->Named Pipes - Enable
--->TCP/IP - Enable
--->VIA - Disable
Or Try the following
Go to Start -> in search type Services.msc. There you will find services which are available in your system.
There look for -> SQL EXPRESS / SQL Server (SQLEXPRESS) -> Right click on it -> then Start it .
If it is already in Start. Just Stop and start or simply Restart it.
I had the same problem and for some reason I had to add the standard SQL port (1433) and then everything worked again. In your case that would be:
string connectionString = #"Data Source=SYAZANA,1433;Initial Catalog=WangSCM;integrated security=true;"

Remote Connection Error in Asp.net

I am trying to make a registration page, that stores Username, password,and email,
but
When ever i try to Connect database using this string,
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["RConnectionString"].ConnectionString);
conn.Open();
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)
I searched everywhere, but it didn't helped me..
The issue starts from web.config and the connection string that is located at RConnectionString according to the code line you give.
Locate this string and fix it to been able to connect to your database.
And some examples here: Setting up connection string in ASP.NET to SQL SERVER

SQL SERVER ERROR (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)

I'm working on a website using ASP.NET, C# and mssql.
When I run the website on our local server it is working fine.
The following error occurs when I run it on a shared server:
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 don't know how to play with connection string now since I'm very new to this.
It is recommend to keep the connection string in web.config.
To create a valid connection string with SQL Server (either located on network or locally), use following steps:
Steps:
Create a Test.UDL file at your desktop.
Double click the file to see undermentioned Data Link Properties
Select provider i.e SQL Server in your case
Provide connection details i.e. server, username, password etc. in Connection tab.
Test Connection on connection tab and press "OK".
Open UDL file in notepad to see valid connection string.
UPDATE
check following link for creating UDL http://msdn.microsoft.com/en-us/library/e38h511e(v=vs.71).aspx
check following link for connection string Setting up connection string in ASP.NET to SQL SERVER

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