Good afternoon.
I'm having troubles getting connected to a Postgres database.
The app I'm working on has to run on .NET 4. I'm using Npgsql, and because I'm limited to .NET 4, I'm using Npgsql version 2.2.7 (I believe 3+ requires .NET 4.5).
The application will be running on the same machine as Postgres is. The database is installed and set up by a third party, and for that reason I'm unable to change the pg_hba.conf file.
My first stab at a connection string looked like this:
Server=localhost;Database=xyz;Integrated Security=true;
But I got this error:
FATAL: 28000: no pg_hba.conf entry for host "::1", user "SYSTEM", database "xyz", SSL off
Researched that error, and tried numerous other variations of the connection string to fix this, including:
Server=127.0.0.1;Database=xyz;Integrated Security=true;
Server=-h 127.0.0.1;Database=xyz;Integrated Security=true;
Server=127.0.0.1/32;Database=xyz;Integrated Security=true;
Server=::1;Database=xyz;Integrated Security=true;
Server=::1/128;Database=xyz;Integrated Security=true;
But nothing works. I either get the
FATAL: 28000 ...
error, or a simple
Failed to establish a connection to ...
The pg_hba.conf file looks like this:
host all postgres 127.0.0.1/32 trust
host all xyz 127.0.0.1/32 trust
host all xyz ::1/128 trust
host all postgres ::1/128 trust
This is all running on a Windows 7 machine, and IPv6 is turned off on the network connection.
It's probably something simple, but what can I do? I can't change the pg_hba.conf file, so how can I tweak my connection string to work?
Try this:
"Server=[your server];Port=[your port];Database=[your database];User ID=[your user];Password=[your password];"
For example:
"Server=localhost;Port=5432;Database=BookStore;User ID=operator;Password=1234;"
at the beginning of your pg_hba.conf file add (the order of entries is important!):
# Type database users auth.method
local xyz all sspi
If you don't want user any password to connections.
(For more info check:
https://www.postgresql.org/docs/9.1/static/auth-methods.html#SSPI-AUTH
https://www.postgresql.org/docs/9.1/static/auth-pg-hba-conf.html
(auth-method -> sspi))
Secound option is add to your ConnectionString as #Cecilia Fernández says.
But then you need to add to your pg_hba.conf file:
# Type database users auth.method
local xyz all md5
Related
I've being trying in vain to solve a problem on a newly created windows server with IIS hosting an ASP.NET application that was copied from another environment. The issue is that I cannot manage to connect to the database when the application tries to open a connection via entity framework.
If this is off topic for SO let me know so I can move to another channel, I thought it belonged here as seems specific to EF.
In detail, I have the following connection strings:
<connectionStrings>
<add name="ApplicationServices" connectionString="Data Source=LOCALCOMPUTER\SQLEXPRESS;Initial Catalog=xxx;Persist Security Info=True;User ID=yyy;Password=zzz" providerName="System.Data.SqlClient"/>
<add name="MembershipConnection" connectionString="metadata=res://*/App_Code.Membership.Membership.csdl|res://*/App_Code.Membership.Membership.ssdl|res://*/App_Code.Membership.Membership.msl;provider=System.Data.SqlClient;provider connection string="Data Source=LOCALCOMPUTER\SQLEXPRESS;Initial Catalog=xxx;Persist Security Info=True;User ID=yyy;Password=zzz;MultipleActiveResultSets=True;Application Name=EntityFramework"" providerName="System.Data.EntityClient"/>
...
xxx, yyy, zzz of course have the proper values. LOCALCOMPUTER is the FDQN of the local computer, which is not on a domain
The first connection string is for the Microsoft login library, while the second uses entity framework from our code.
When I browse to the site, I can successfully access the login form, and if I try to insert a wrong password i get a message saying so, meaning the application managed to check the database using the first connection string, but when i insert a correct one, i land on an exception as soon as the code tries to create a context.
The underlying provider failed on Open.:
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 - The wait operation timed out.)
In the event viewer it tells me that the user has been authenticated via Authentication Type: Forms , which I assume it means the auth system (the one using ApplicationServices connection string) is working, the stack trace confirms that the error occours when I try to use EF in code, meaning the DB has been used succesfully to check user credentials
note that:
The web app works in other environments
I can connect to the sql server using the credentials via SSMS
I've assigned a local windows account to the app pool that can also access the database, and tried changing to Integrated Security=SSPI
Both .Net 3.5 and .Net 4.8 are installed
The database is on the local machine and has been restored from a dump of the other one, its users have been mapped, and to rule out issues i gave it ample authorisations with dbowner datawriter and datareader
I've been trying to fix this since a couple days checking similar issues on SO with no avail and I don't really know how to proceed, is there something I can do to troubleshoot the issue?
Apologies, I've found out the answer, and it's specific to the code base. Apparently the connection string was being ignored (despite being perfectly usable) in favour of data saved in a table.
Had to contact the previous developer to find out, guess it's a good example of how important is to document your code
I'll close the thread, thanks for all who tried to help
when Our WinApp is idle for while around 8-10 minutes ,and try to do something like get list of customers, we got this error "The underlying provider failed on Open"
i use EF6.1 & MSSQL 2008 r2 Here Is my connection string :
<add
name="MISSystemEntities"
connectionString="metadata=res://*/DB_Model.csdl|res://*/DB_Model.ssdl|res://*/DB_Model.msl;
provider=System.Data.SqlClient;
provider connection string="Data Source=10.10.0.3\r2;Initial Catalog=MISSystem;User ID=user;Password=pass;MultipleActiveResultSets=True""
providerName="System.Data.EntityClient"
/>
Sql Option Auto Close Is Off
Distributed Transaction Coordinator Is Active for Clients "actually We don't use it"
have ping to server without any time aout at the same time that error occurs
test with domain administrator rights and still have problem
also We Test Connection time out and query execute time out with random values:(
Its seems related the connection issue.
Seems like a connection issue. You can use the Data link properties to find if the connection is fine. Do the following,
Create a blank notepad and rename it to "X.UDL" Double click open it, under connections tab choose the server name/enter the name use the correct credentials and DB OK to save it.
Now open the file in Notepad and check, compare the connection string properties with this..
Refer link:- Entity Framework The underlying provider failed on Open
The underlying provider failed on open entity framework
Please read the link
Here is same issue explain to resolve by Microsoft team member.
http://blogs.msdn.com/b/dataaccesstechnologies/archive/2012/08/09/error-quot-the-underlying-provider-failed-on-open-quot-in-entity-framework-application.aspx
my problem (issue) was SQL server Connection pooling :D
the pooling store the last request time and when u idle for while around 5-10 min and then when it receive request it'll answer the request ( !??! ) but after that the pooling terminate your connection and your next request throw the exception :(
for now i set timer to each 30s send a request to DB !
i was using entity framework 6 with wcf web service with "integrated security=true" in the wcf web.config. the error message was similar. what was happening, iis was using the application pool credentials to connect to the database. once i specified a user account in the connection string, it worked like a charm...
hope this helps.
I have a WinForms application that connects to a SQL Server database. I use the following connection string
data source=MyPC\SQLEXPRESS;initial catalog=MyDB; trusted_connection=true;
Problem is, I need to create an installer for the application, but I do not know the name of the target computer. How can I define my connection string, so it will work on any computer the application is installed on?
Thank you for your help.
I still don't have the privilege to comment, so I'm posting as an answer.
using "Localhost" in the data source would do the trick
so your connection string will be like this:
connectionString="data source=localhost\SQLEXPRESS;initial catalog=MyDB; trusted_connection=true;"
I have a connection string to a local database which works ok.
<connectionStrings>
<add name="Entities"
connectionString="metadata=res://*/RNADataModel.csdl|
res://*/RNADataModel.ssdl|
res://*/RNADataModel.msl;
provider=System.Data.SqlClient;
provider connection string="
Data Source=my-localhost;
Initial Catalog=my-db-name;
Integrated Security=True;
multipleactiveresultsets=True;
App=EntityFramework""
providerName="System.Data.EntityClient"/>
</connectionStrings>
However I cannot figure how to connect to a remote database succesfully.
I have tried to add User ID=user; Password=pass; and also disabled Integrated Security but the server fails to connect.
Is there a way to fix the connection string or some other workaround to connect to the remote database?
EDIT:
The error comes from my web app every time the connection string is not correctly specified:
Server Error in '/' Application.
The server was unable to process the request due to an internal error. For more information about the error, either turn on IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the <serviceDebug> configuration behavior) on the server in order to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework 3.0 SDK documentation and inspect the server trace logs.
and
System.Data.EntityException throws: {"The underlying provider failed on Open."}
If I use SQL Server management studio I can see the database on the server and credentials works fine. Might be some firewall configuration, any suggestions?
You need to change Data Source=my-localhost to
Data Source=ServerName\InstanceName
Don't forget to specify the correct UserName & Password
I managed to access the customer's server, so following this guide http://blogs.msdn.com/b/walzenbach/archive/2010/04/14/how-to-enable-remote-connections-in-sql-server-2008.aspx
I have enabled the remote connection. The Connection string was fine. Thanks the comments
My sqlconnection is
SqlConnection(#"Data Source = John\Administrator; Initial Catalog = TicketingSystem; Integrated Security = true;");
I try to connect to the server but i cant this error pops up
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 think that the error is in the Data Source but I cant find it. When I open Microsoft SQL Server Management Studio it says that my server is "John" and the Connection is "John\Administrator" so please help me.
if the server is actually called 'John', then that is your data source. When you're running locally, you could probably just set Data Source=(local), tho.
Other than that, you'd need to specify a user to connect with
http://connectionstrings.com/
An easy way to get your connection string is
create a file called x.udl
double click on it
Follow wizard
open x.udl file in notepad
and inside you will find your connection string.
When I open Microsoft SQL Server
Management Studio it says that my
server is "John" and the Connection is
"John\Administrator" so please help
me.
That means you're logged on to your server's default instance (John) as Administrator. Remove the \Administrator part, and you should be good to go!
var cn = new SqlConnection(#"Data Source = John; Initial Catalog = TicketingSystem; Integrated Security = true;");
You can get your connectionstring from SQL Server Management Studio from the properties window.
Just click on the John\Administrator node, then press F4 to open the properties window, and search for the connection string there...
The Integrated Security=True part of your connection string means "connect as the current user". When you run an asp.net page, the current user by default is a special ASPNET account. You can "impersonate" a different user, but I'm guessing you haven't done that and the ASPNET user doesn't have access to your database.
It's possible that your server isn't configured to allow remote connections. You can check this in the SQL Server Configuration Manager tool.
Have a look here too.
Your Data Source is the server. So you only need "John", not "John\Administrator", that's not a valid data source. You're using integrated security which means it will use the same username as the program is running under and it's credentials, if it's on the domain.
Data Source = John\Administrator
Specifying John\Administrator as your Data Source, means ADO should connect to the SQL instance named "Administrator" on the server "John". Although instances are quite useful, I don't think that's what you want. (SQL Instances allow you to run multiple copies of SQL Server on one server)
As "d." mentioned, you will need to change Data Source to the correct server name or (local) ((local)\SQLEXPRESS if it's SQL Express).
Also, Integrated Security=true means that the user running ASP.NET, or at least the AppPool, will need access to the database. (The default is NETWORK SERVICE on pre-Windows 7, IUSR / IIS_USRS on 7).
If, however, you use ASP.NET windows authentication with <identity impersonate="true" /> then the user accessing the site will need access to the database.
Create a file called x.udl
Double-click on it
Follow the Wizard
Open x.udl file in notepad
and then you will find your connection string inside.