I am trying to learn ADO.NET to connect with SQL Server ...
I install SQL Server with Visual Studio ....
there is data base called "Northwind" as example with it ...
I am trying to read this database , I wrote this code ...
using System;
using System.Data;
using System.Data.SqlClient;
namespace DataSetReaderFromSQL
{
class Program
{
static void Main(string[] args)
{
SqlConnection connection = new SqlConnection(#"Data Source=(local);Integrated Security=SSPI;" + "Initial Catalog=Northwind");
connection.Open();
SqlCommand command = connection.CreateCommand();
command.CommandText = "Select CustomerID , CompanyName from Customers";
SqlDataReader reader = command.ExecuteReader();
while (reader.Read())
Console.WriteLine(reader["CustomerID"] +""+ reader["CompanyName"]);
reader.Close();
connection.Close();
}
}
}
When the application runs, it's take a little of time then throw exception when it trys to open connection ...
the text of the exception :
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 am using Windows 7 as my operating system, and I put username on my account ...
I am sure that SQL Server was installed on my computer
where is my error ??
Either
You haven't configured Sql Server to allow remote connections, as the error message tells you =)
Your datasource is wrong. Try .\SqlExpress or just . Ordinarily when Visual Studio installs Sql Server Express, it installs it as a named instance called SqlExpress.
Visual Studio includes Express edition of SQL Server. Thus, your connection string should most likely look like "Data Source=(local)\sqlexpress;...".
If you want a quick & easy way to try different connection strings, I suggest DatabaseTester (disclaimer - I wrote it). It's free and a very easy way to test. Also, for figuring out connections strings ConnectionStrings.com is your best friend.
Related
I have an issue trying to manually connect to a sql server on my network.
I have a web API with a conn string that works fine, I have a VS2015 winforms project i set up to test the conn using the VS tool to connect, this also works fine.
However when i try to connect via SQLconnection it fails and says the server cannot be found or isnt accessable.
So heres the test code...
string connectionString = #"Data Source=test1\test1;Initial Catalog=my_test;Integrated Security=True;";
using (SqlConnection connection =
new SqlConnection(connectionString))
{
// Create the Command and Parameter objects.
SqlCommand command = new SqlCommand("", connection);
// Open the connection in a try/catch block.
// Create and execute the DataReader, writing the result
// set to the console window.
try
{
connection.Open();
SqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine("\t{0}\t{1}\t{2}",
reader[0], reader[1], reader[2]);
}
reader.Close();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Console.ReadLine();
}
Now i dont really care about results or anything i simply need to establish a connection. I cant figure out why it throws this error, when my Web API works and the VS tool for connection to DBs works fine too.
I have checked the server and enabled named pipes too just to make sure.
Any ideas?
EDIT:The error i catch...
{"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)"}
happens after about 15 seconds trying to open the connection.
The thing is this connectiin string i tried is the exact same string used via the SQL tool, I did this so i knew i had a valid string.
ODBC connection also falls over with the same message.
I checked from my machinbe is i can listen to port 1433 but it says the server isnt listening.
However looking at the server its set to dynamic ports with a range of any to 41934, so im at a loss as to why it says its not listening evenb though its to dynamic ports
EDIT2: Well, must be permissions or drivers... just tried the exact same code and worked instantly...
This is diving into the realm of the unknown i feel. might ask for deletion of the question if no solution is found
I think that i see the problem:
string connectionString = #"Data Source=test1\test1;Initial Catalog=my_test;Integrated Security=True;";
Integrated Security is used for local logins, You could make an account in the database and change the connection string to:
string connectionString = #"Data Source=test1\test1;Initial Catalog=my_test;User id=<Username>;Password=<Password>;";
I hope this helps!
Using SSMS and Visual Studio 2015's Server Explorer tab under Data Connections, I can execute queries on remote server KOSH without issue. Why is the MVC application running locally in Visual Studio/IIS Express unable to do the same?
Using VS2015's connection Properties, I get its connection string:
Data Source=123.456.78.9;Persist Security Info=True;User ID=Foo;Password=Bar
Using that connection string, the MVC application is greeted with:
"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)"
Inner exception message:
"The network path was not found"
I know the server/firewall/network settings are correct. That leaves the application.
using(var connection = Database.Connection(conInfo.ConnectionString, provider)) {
// rowCountSql: SELECT SUM(rows) TM_ROWCOUNT FROM sys.partitions
// WHERE object_id = object_id(#tableName) and index_id IN (0,1)
// Any other SQL yields same error
var countTask = connection.QueryAsync(rowCountSql, new { tableName = Editor.TableName });
}
Async is used because the Oracle version of the query can take several seconds to return.
The application should be correct because it connects to the same server from home (also the server's location) and to identical databases in remote data centers running 2008R2 to 2014 without a problem.
Database.Connection() is:
// This is unlikely to be the problem as it is very well tested
public static DbConnection Connection(string connectionString, string databaseProvider) {
DbProviderFactory databaseFactory = DbProviderFactories.GetFactory(databaseProvider);
DbConnection connection = databaseFactory.CreateConnection();
if(connection != null)
connection.ConnectionString = connectionString;
return connection;
}
I bet I am missing something simple, but I would be grateful for help on what that could be.
As I said in comments, maybe the piece of your code:
conInfo.ConnectionString
does not contains the correct connection string you want.
Check it out
Hi I am trying to connect to a local SQL Server Compact database (.sdf) in a Windows forms project and have been facing this problem for quite some time. I am not allowed to use datasets for the project, all the queries and connections are written in the application.
System.Data.SqlClient.SqlException
A network-related or instance-specific error occurredwhile 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)
Code:
SqlConnection _Connection = new SqlConnection(ConfigurationManager.ConnectionStrings["restaurant"].ToString());
SqlCommand _Command = _Connection.CreateCommand();
_Connection.Open(); // <- throws exception
To connect a Sql Server Compact you need a different set of classes contained in the namespace SqlServerCe (SqlCeConnection, SqlCeCommand and so on....)
SqlCeConnection _Connection = new SqlCeConnection(ConfigurationManager.ConnectionStrings["restaurant"].ToString());
SqlCeCommand _Command = _Connection.CreateCommand();
_Connection.Open();
of course, you need to reference the assembly that contains the above mentioned classes.
System.Data.SqlServerCe.dll (ADO.NET provider)
and add the using statement
using System.Data.SqlServerCe;
We have a "legacy" application, which uses ODBC connections to an underlying database, which can be Access, Oracle or SQL Server. For unit (or, perhaps more properly, "integration") test purposes, I'd like to hook up a SQL Server 2012 LocalDB instance. However, I cannot figure out a correct ODBC connection string to use.
I have tried:
[TestMethod]
public void OdbcConnectionToLocalDb()
{
string connectionString = "DRIVER=SQL Server Native Client 11.0;Trusted_Connection=Yes;SERVER=(localdb)\v11.0;Description=LocalDB;";
using (OdbcConnection connection = new OdbcConnection(connectionString))
{
using (var command = new OdbcCommand("select * from Person", connection))
{
connection.Open();
// ...
}
}
}
However, when the connection is opened, the following exception is thrown:
System.Data.Odbc.OdbcException: ERROR [08001] [Microsoft][SQL Server Native Client 11.0]Named Pipes Provider: Could not open a connection to SQL Server [67].
ERROR [HYT00] [Microsoft][SQL Server Native Client 11.0]Login timeout expired
ERROR [08001] [Microsoft][SQL Server Native Client 11.0]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.
Is it possible to connect to a SQL Server 2012 LocalDB via an ODBC connection/driver? Is it possible to connect to a specific file?
[EDIT]
Garrett points out it is possible, great. I must have the connection string wrong, so my question really should be: what should the connection string be?
You need to specify your connection string like this:
Provider=SQLNCLI11.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=TestDB;Data Source=(localdb)\v11.0
The main thing I think is that you reference it as a data source rather than server.
Yes, it's possible. Make sure you install the latest driver: SQL Server Native Client "Denali" (for ODBC and OLE DB).
Look here for more info:
http://blogs.msdn.com/b/sqlexpress/archive/2011/07/12/introducing-localdb-a-better-sql-express.aspx
Im facing problem with database connection on windows Application Database Connection c#... here is my connection ,,, PC2 is PCNAme
private static SqlConnection con = new SqlConnection(
"Data Source=PC2\\SQLEXPRESS; Initial Catalog=Database1;Integrated Security=True"
);
when I run the form I get this unhandled exception on con.Open();
sqlException was unhandeled:
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)
hope some one can help Im trying to solve it for many hours but not working.
Check this trouble shoot steps on MSDN:
The SQL Server client cannot connect to the server MSDN
And much better if you separate your connection string to your ado.net sql connection.
private const string _thisConnectionString = "Data Source=PC2\\SQLEXPRESS; Initial Catalog=Database1;Integrated Security=SSPI";
Use the "Using" Statement ensure that you always close your Connection.
Best Practices for Using ADO.NET MSDN
using (var conn = new SqlConnection(_thisConnectionString))
{
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "Your SQL Query STuff";
conn.Open();
}
Regards
Try This:
private static SqlConnection con = new SqlConnection(
"Data Source=PC2\SQLEXPRESS; Initial Catalog=Database1;Integrated Security=True"
);
Go to SQL Server Configuration Management -> Click on SQL Server Services
Verify SQL Server and SQL Server browser both are running. you can see a Greed play button there. if it's not running right click on the service which shows Red, go to properties, Click Built in Account and Press Apply then OK, There try to start by right click.