I created a database using SQL Server Express from Visual Studio 2012 and I fail to open a connection pointing that database.
I've tried many way like for example:
SqlConnection connectionLocale = new SqlConnection(#"Data Source=(LocalDB)\\v11.0;AttachDbFilename=C:\Users\Max\Desktop\presentoir\Application\WpfAppTest\BDD.mdf;Integrated Security=True");
But I keep on getting the same error message :
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) (Microsoft SQL Server, Error: 1326)
As I am a total beginner, even with two days of research, I really can't figure out what the problem is.
I can get a connection using :
SqlConnection connectionLocale = new SqlConnection("Data Source=(LocalDB)\\v11.0;AttachDbFilename=|DataDirectory|BDD.mdf;Integrated Security=True");
But I can't change my database using C# code by connecting like this (I think it creates a temporary database in appdata, and that all the modifications are done in this database).
Every idea helping me to create a connection to my database is welcome.
Okay, a coworker found the solution.
God, it was obvious...
With the # behind the string, the correct data source was :
#"Data Source=(LocalDB)\v11.0
and not :
#"Data Source=(LocalDB)\\v11.0
Related
I am trying to create a local database using MySql in Visual C# but connection is not getting established in the code but when i add the server in the server explorer under data connections its working. I tried test connection it says connection succeeded but its not working in the code.
string connStr = "server=localhost;user=root;database=entry_database;password=superadmin";
con = new SqlConnection(connStr);
This throws an error saying
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)
You cannot use the SqlConnection class to connect to a MySQL server; that is for Microsoft SQL Server only.
Instead, install the MySqlConnector NuGet package and use the following code:
string connStr = "server=localhost;user=root;database=entry_database;password=superadmin";
using (var con = new MySqlConnection(connStr))
{
// ...
}
Your connection string is wrong.. change keys "user" to "Uid" and "password" to "Pwd".
follow eg:
string connStr = "server=localhost;Uid=root;database=entry_database;Pwd=superadmin";
con = new SqlConnection(connStr);
Correct, the format used by you to create the connection string is incorrect, giving you the error you mentioned above.
Actually, the way the connection string is written in MS-SQL is very different from MY-SQL. Every database has its own way of connecting and its individual connection tags:-
Please find the list of connection details for MS_SQL below. This would help you not only in the current mentioned scenario but also will provide a reference for future changes:-
https://www.connectionstrings.com/mysql/
I am working with SQL Server. I used all connection via :
SqlConnection con = new SqlConnection("data source = .; database = xyzDatabase; integrated security = true");//developed with developer edition.
Now I want to run my application on SQL Server Express, so I used this :
SqlConnection con = new SqlConnection("data source = .\\sqlexpress; initial catalog = xyzDatabase; user id = sa; password = 123");
Point to remember is, I am creating my xyzDatabase at runtime on form load event. But when I execute the program 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: Named
Pipes Provider, error: 40 - Could not open a connection to SQL Server)
(.Net SqlClient Data Provider)
Import the namespaces
using System.Data.SqlClient (if using C#)
or
Imports System.Data.SqlClient (if using VB#)
Your Sql connection object with connection would be like this:
SqlConnection con = new SqlConnection("Data Source=.;Database=xyzDatabase;User Id=sa;Password=admin#123;");
If still your error not resolved, it might be the problem of incorrect installation of MS-SQL SERVER instances.
http://blog.sqlauthority.com/2009/05/21/sql-server-fix-error-provider-named-pipes-provider-error-40-could-not-open-a-connection-to-sql-server-microsoft-sql-server-error/
Hope it might be helpful.
you must active sa user in sql express edition.
SqlConnection cn = new SqlConnection("datasource=.\sqlexpress; initialcatalog=yzDatabase; userid=sa;password=123");
I am using Visual Studio and trying to connect to the Northwind database. I use the following connection command...
Data Source=C:\\Program Files (x86)\\Microsoft SQL Server Compact Edition\\v3.5\\Samples\\Northwind.sdf;Initial Catalog=Northwind;Integrated Security=SSPI"
I have also tried
Data Source=(local);Initial Catalog=Northwind;Integrated Security=SSPI
both cases 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: SQL
Network Interfaces, error: 26 - Error Locating Server/Instance
Specified)
I can connect to an online database but not on a remote one. I have checked the config manager and all services are running.
Any helps please
there are lots of collections of connection strings so you can get help from here...
http://www.connectionstrings.com/sql-server-2008
The Visual Studio has tools to connect to databases. Using Server Explorer, you can choose which SQL Server you want to connect to and then choose the database from a list. Once you have successfully connected to one, its properties mention the connection string to use. No need to guess.
I'm trying to connect to a database but nothing I try works.
SqlConnection conn = new SqlConnection(#"Data Source=C:\Users\Gerard Foley\Desktop\Northwind.sdf");
conn.Open();
No matter what I try I just get the 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)
I stole the connection string from Database Explorer -> Properties -> Connection String. What am I missing? I can get the tables to show up in a DataGridView fine (by dragging from Data Sources), but I want to use my own UI and queries. I just can't seem to figure this ADO thing out.
Using c# express 2010 and sql server express 2008.
for the proper connection string to use to connect to SQL Server have a look at:
http://connectionstrings.com
the connection string you are using now is strange, it should contain server name and database name, see link above for examples...
GOT IT. I should have been using Sql*Ce*Connection. The connection string was fine.
You need to specify 'AttachDbFileName' in the connection string. See the examples for sql server express here: http://www.connectionstrings.com/sql-server-2008.
I have a sqlconnection problem. i have perfectly connection to sql server when i m using sqldatasource.
but when i m try use SqlConnection object throw an exception.
string qstring = "Data Source=****;Initial Catalog=**;User ID=**;Password=**";
SqlConnection con = new SqlConnection(qstring);
con.Open(); (exception thrown here)
exception is : 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)
Sql server is in different machine and i can connect using SqlDataSource object for example i can bind a grid by that way. But i must connect with SqlConnection object
Connection string is true because i have it from SqlDataSource...
Thx for your helps..
You might also want to make sure that the SQL Server is set up to accept remote connections.
(for sql2005 Configuration tools -> Surface AreaConfiguration-> Services and Connections -> database, Local and remote connections )
Is your SQL server is in the same machine ? if yes , Check the SQL server service is running , If its in a different machine,check your development machine has connectivity to it .You can ping to that machine to verify this. You can also check the surface area connection wizard to check whether the SQL server support remote connections , as snomag said
If the code that you have shown is what you have then I'm not surprised that you couldn't connect.
You'll need to have the correct Data Source, UserID and Password in qstring. As it stands asterisk characters won't mean anything.
A new point
A further point, which is often forgotten, SQLConnection will only work with Microsoft SQL Server. If your SQL is provided by a different manufacturer the use OleDBConnection instead.