What connection string should I use if SSMS connects to it using simply machine name, without instance name?
I mean it connects using the following string: PCName
I used to connect using PCName/SQLExpress. I cannot set correct connection string in my app in order to connect app to database on this machine.
How can I check what data source I should use? I've checked in Sql Server configuration that server instance named as SQLEXPRESS.
So I tried data source as:
.\SQLEXPRESS
PCName\SQLEXPRESS
.
I'm trying to connect to a service-based database, located in my app folder. So I'm using the following connection string:
data source=PCName;attachdbfilename=|DataDirectory|\spareparts.mdf;integrated security=true;user instance=true;multipleactiveresultsets=true;App=EntityFramework;
If SSMS connects via PCName then your application should be able to use Data Source=PCName. However it depends on whether your application is on the same machine as SSMS or not. If on a different machine it might not be able to connect for a variety of reasons. We can't speculate what the problem might be if all you do to describe the issue is "It won't connect" - what does that mean? Do you get an error message? If so, what is it? Make sure:
SQL Browser service is started
TCP/IP is enabled
Add Network=DBMSSOCN; to the connection string
You've also tried the IP address in addition to PCName
Firewall isn't blocking the SQL Server port
Related
I am currently implementing a UWP program for an existing database. I took this article as a basis.
https://learn.microsoft.com/en-us/windows/uwp/data-access/sql-server-databases
When running, I get an exception:
System.Data.SqlClient.SqlException" в System.Data.SqlClient.dll
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: TCP Provider, error: 25 - Connection string is not valid)
This seemed strange to me, since a WPF application with the same connection string works fine. Next, I decided to install a database instance on my computer and export some of the data to a local database. To my surprise, after replacing the connection string from:
Data Source=sqlserver\sqlexpress
to
Data Source=.\sqlexpress
UWP program read this from the database on my computer.
I also read this article to make sure that the remote database is configured correctly. https://www.lansweeper.com/knowledgebase/a-network-related-or-instance-specific-error-occurred/
As I said, WPF programs work with this database perfectly. What are the ways to check why the UWP doesn't want to communicate with the database?
to make it clear whether the remote server is available in principle, I apply the output of the TNC command:
tnc sqlserver -p 1433 -I detailed
ComputerName : sqlserver
RemoteAddress : 192.168.10.11
RemotePort : 1433
NameResolutionResults : 192.168.10.11
MatchingIPsecRules :
NetworkIsolationContext : Private Network
InterfaceAlias : Ethernet
SourceAddress : 192.168.10.20
NetRoute (NextHop) : 0.0.0.0
TcpTestSucceeded : True
Connection string look like:
private string connectionString = #"Data Source=sqlserver\sqlexpress;Initial Catalog=TestCatalog;User ID=*;Password=*";
The same connection string is used in VS. VS shows the contents of the table without problems. I can also delete or add new lines in the VS editor.
I'm talking about a remote database. In VS server Explorer I have a Data Connection where I am connected to a remote database. I can safely edit remote database data in VS (add, delete and update). I see the connection string and originally used it as the connection string in UWP app.
You have already taken a look at this microsoft link here. Long story short, have you followed the proposal below?
Trouble connecting to your database?
In most cases, some aspect of the SQL Server configuration needs to be changed. If you're able to connect to your database from another type of desktop application such as a Windows Forms or WPF application, ensure that you've enabled TCP/IP for SQL Server. You can do that in the Computer Management console.
Check to see if you have followed the rest of the solution properly. You might need to enable the tcp port from the window firewall.
Go to firewall -> Inbound Rules -> Add TCP:1433 in the rule.
Also since the error is about the connection string, try to use only the server name/ ip/ or hostname, without the server instance.
You can also add the port number and see if this works for you. When you add it, sql server ignores the instance name (as different instances require different ports to work, so it can work as a unique identifier).
Edit: How to create a valid connection string:
Look at this answer here: How to get the connection String from a database
I am developing a program with C# and WPF. I want the data to be stored in an SQL Server database. I made a connection string with the instance name in my PC, and that worked. But when I want to connect through the Internet with an IP address, I get some errors:
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. (TCP Provider,
error 0 - No connection could be made because the target machine
actively refused it.)
I enabled TCP/IP, allowed remote connection in SQL Configuration Manager, opened a port of 1433 in my firewall, but still I am getting this error.
My connection string is this:
String connString = #"Network Library=dbmssocn;
Network Address=127.0.0.1,1433;
Integrated security=SSPI;
Initial Catalog=db";
SqlConnection conn = new SqlConnection(connString);
conn.Open( );
Where is my mistake?
There is very slight error in your connection string and honestly I can't blame you for that as it is very weird way in which SQL Sever is behaving. I'm not sure if this error lies in connection provider side or SQL Server instance side. Name of Network Library that your application is using to connect to the SQL Server using dbmssocn(Win32 Winsock TCP/IP) should always be mentioned in capital letters. Though I didn't see any relevant MSDN documentation from MS to support my statement but it actually worked when I did so. Here is the connection string that you should be using to fix the error.
String connString = #"Network Library=DBMSSOCN;
Network Address=127.0.0.1,1433;
Integrated security=SSPI;
Initial Catalog=db";
Seriously, I got freaked out in reproducing your issue as instead of copying the connection string from your question I copied it from some other blog :). But all is well that ends well. I've also assumed that a database named "db" actually exists on the default (NOT named instance) instance of the sql server you are connecting to when typing this answer. If changing the casing of network library name in connection string doesn't help then double check that database "db" must exist for a sql server default instance to which you are connecting to. In case you are using a named instance of sql server in your installation then that instance name should also come in the connection string.
Configure your SQL Server to allow TCP/IP connections. Go to SQL Server Configuration Manager -> network then protocols for your SQL Server named instance -> TCP/IP.
See this image!
I'm having trouble connecting to a SQL Server on a machine in our LAN.
i have done the following :
1.) Made the IP of the machine running the Server 10.0.0.7 and made the IP of the other machines on the LAN IP 10.0.0.X . There is no internet on the LAN(and it will stay that way), changeing IP is permitted.
2.)Enabled remote connection by doing This
3.)Used the appropriate connection string.
Now my only Question that remains is regards to the connection string of those who wish to connect on the server, here is the current Con-string:
string sConnection = #"Server=10.0.0.7\MARNUS-PC\MARNUS_HOME; User ID=MARNUS-PC\MARNUS_HOME; Password=somepassword; Initial Catalog=TestDB;";
My questions are :
1.)What do i put the Server portion? here is my Server name and instance name acording to
the management studio - Server name : MARNUS-PC\MARNUS_HOME , Instance name : MARNUS_HOME.
2.)What do i use as user ID? I wish to use Windows authentication instead of sql server authentication(i have enabled both on server), so how should the connection string change and how to do i allow a user from the server's side on the management studio(if needed)?
3.)I asume if I use Windows authentication i do not need the password part of the Con-String?
I apologize for all the questions,but i was taught MS Access and is now making the switch to SQL Server by myself.
Your connection string must be something like....
string sConnection = #"Server=MARNUS-PC\InstanceName; User ID=MARNUS-PC\MARNUS_HOME; Password=somepassword; Initial Catalog=TestDB;";
Instance name is the Sql Server Instance name.
If you are not Sure about your instance name execute the following statement in your Sql Server Management Studio
SELECT ##SERVERNAME
It will return the [ServerName\InstanceName] you can pass the whole returned string to your connection string are your Server name Server=ServerName\InstanceName;
Windows Authentication
To use windows authentication you will have to a connection string something like this..
string sConnection = #"Server=MARNUS-PC\InstanceName; Initial Catalog=TestDB; integrated security=SSPI";
The IP address identifies the computer, so you wouldn't use both the IP address and the computer name. You can use the IP address in the server setting:
Server=10.0.0.6\MARNUS_HOME;
or you can use the computer name:
Server=MARNUS-PC\MARNUS_HOME;
You are correct that you shouldn't specify any password when you are using windows authentication, and you shouldn't specify any user name either, but you need to specify that you are using it:
Trusted_Connection=Yes;
I have two .net solutions.
They both have this code:
var connectionString = "Server = ServerName; Database = DatabaseName; Trusted_Connection=True;"
var connection = new SqlConnection(connectionString);
connection.Open();
connection.Close();
And they both use complitely the same connectionString. And they connect to MSSQL Server;
And in the first solution connection.Open() succeeded and in the second one it failed.
Error message : Named Pipes Provider, error: 40 - Could not open a connection to SQL Server
And every time I create new solution it fails. So this connection only works in one specific solution. And also, my teammates tested this and didn't have such issues.
Can you help with hints why it can be so?
Check that your SQL server has the TCP/IP protocol enabled and if it is using dynamic ports, ensure that the SQL Browser service is running.
Make sure that any firewall software (windows firewall etc.) has an exception added for the particular exe (the sqlservr.exe file gets copied into the instance folder, which will be in C:\Program Files\Microsoft SQL Server\{instance name}\MSSQL\Binn, where instance name might look something like MSSQL11.SQLEXPRESS) or TCP port 1433 or UDP port 1434 (TCP 1433 for the SQL service itself assuming standard settings, UPD 1434 for the SQL Browser Service).
Check that the user account used to access the server (it should also have sufficient permissions and the login should be enabled), in this case it will be whatever windows account you are logged in as or whatever account your IIS application pool is running as because you are using Trusted_Connection=True.
Also check that you have an up-to-date SQL Client on your machine, you can get the latest version for windows here.
Open Sql Server Configuration Manager and make sure that the Named Pipes option is enabled for your Sql server instance.
Sorry for disturbing you. My problem was my inattentiveness. I created soluiton on another network machine.
I am creating desktop application in c# but i wont to use Online Database created in mysql.
String mysqlConnectionString = "Server=216.14.120.105;Database=xxx_keys;UID=xxx_root;Password=xxx;Port=3306";
MySqlConnection connection = new MySqlConnection(mysqlConnectionString);
connection.Open();
this is the code i am using but i got an error unable to access host.
where i am wrong and if you have any proper code or details then give me.
If this is a MySQL database in local server user "localhost" for server IP as georgi-it also told. But if this is an external database first try to open a telnet connection on dos-prompt to see if there is some firewall block or something like that:
telnet 216.14.120.105 3306
if you don't get an error message and see a blank page then it means you can reach mysql server