I'd like to know how to link my WCF application with a remote SQL Server database. By remote, I mean that is on the same network than me but not on the same computer/project.
I've the controll of the computer where the database is stored on.
What I've done so far : create my WCF application and try to add an ADO.NET connection. My issue : where to find the name of the server ? (and also : is it the good way to proceed ?).
Thanks !
where to find the name of the server?
Three options:
whoever "owns" the database server tells you the details, and you put them in a configuration file (or some other configuration system)
whoever "owns" the database server tells some key user the details, and the user puts them into a screen / api in the application
something like the above, but you try to discover sql servers at runtime via SqlDataSourceEnumerator (not a fan of this option, to be honest)
Conntion string should look like
Server=myServerName\myInstanceName;Database=myDataBase;User Id=myUsername;Password=myPassword;
In Place of myServerName you can use IPAdress of machine
I suggest you add connectionString in the Web.config file of the application
<add name="connectionString"
connectionString="Data Source=ServerName/PC-Name;Initial Catalog=DatabaseName;User ID=userid;Password=pass"
providerName="System.Data.SqlClient" />
Use the connection string in your code/Logic
string conn = ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString;
I moved a webapp from my personal machine to my work machine, along with the database I've been using to test. When clicking the submit button that inserts the data, I get the error, can't find server/instance. I'm thinking that being on a domain here is part of the problem. Here is my connection string, and I've tried several forms of it already.
Data Source=\\bkirkland_lpt.domain.com\brandon;Initial Catalog=STATUS;integrated security=SSPI;persist security info=False;Trusted_Connection=Yes;");
I see a couple problems here.
First, it looks like you are using the wrong data source. The data source should be in the format [ServerName]\[InstanceName]. Based on your code, I would suggest
Data Source=bkirkland_lpt.domain.com\brandon;Initial Catalog=STATUS;integrated security=SSPI;persist security info=False;Trusted_Connection=Yes;
Additionally, I notice you are using Integrated Security. This means that the user you are running under must be granted permissions on the database. My guess is that your domain user does not have access to the database that you moved.
\bkirkland_lpt.servicesource.com\brandon is a shared folder path, not a host name. Try bkirkland_lpt.servicesource.com
Try to enclose the server name in []. Try to replace the servername with localhost and see if it makes any difference (if it is all on your local machine). I also would use proper casing and True vs Yes as parameter value.
Data Source=[bkirkland_lpt.domain.com]\brandon;Initial Catalog=STATUS;Integrated Security=SSPI;Persist Security Info=False;Trusted_Connection=True;
Data Source=localhost\brandon;Initial Catalog=STATUS;Integrated Security=SSPI;Persist Security Info=False;Trusted_Connection=True;
i am making a simple c#.net winform application with a form1, which will connect to sql server.
i want that before establishing a connection to sql server , the application asks the user to enter the login name & password to connect.
for this what should i do:
take the login name & password in two text boxes & pass them the to the connection string
or
should i pass them to the app.config file & then use the string from app.config file in the form1.cs?
will this be ok with the security issues? if not, then what are the other ways of implementing this task?
I would do this:
use a SqlConnectionStringBuilder component
define things like server name, database name etc. from your app.config
that component also has two properties for user name and password - fill those from a dialog box where you prompt the user for this information
that SqlConnectionStringBuilder then gives you the proper connection string to use for connecting to your SQL Server
Update:
My suggestion would be to store the basic connection string like this:
<configuration>
<connectionStrings>
<add name="MyConnStr"
connectionString="server=A9;database=MyDB;" />
</connectionStrings>
</configuration>
Then load this "skeleton" connection string (which is incomplete - that alone won't work!) into your SqlConnectionStringBuilder:
string myConnStr = ConfigurationManager.ConnectionStrings["MyConnStr"].ConnectionString;
SqlConnectionStringBuilder sqlcsb = new SqlConnectionStringBuilder(myConnStr);
Then grab the user name and password from the user in a dialog box and add those to the connection string builder:
sqlcsb.UserID = tbxUserName.Text.Trim();
sqlcsb.Password = tbxPassword.Text.Trim();
and then get the resulting, complete connection string from the SqlConnectionStringBuilder:
string completeConnStr = sqlcsb.ConnectionString;
using(SqlConnection _con = new SqlConnection(completeConnStr))
{
// do whatever you need to do here....
}
Pass the login to the connection string. app.Config is not a place to store user interaction.
Another way of implementing it might be to authenticate on the SQL server with Windows authentication. That way the local Windows user can have certain security privileges on the database and the user of the application would net necessarily have to enter any credentials.
What are the credentials used for? Are they used for establishing a connection with the database, or to access a user account entry and security privileges in the application?
For securing strings, use SecureString Class.
Sql authentication details is always kept seperate from application authentication details(There are exceptions...eg: ur making ur own version of sql server client)
Keep your database connection details in app.config.
It should Ideally contain one user with app level restrictions enabled.
The Login you speak about is an authentication module which exists in C#. eg: windows authentication,forms authentication etc.
I was using an .mdf for connecting to a database and entityClient. Now I want to change the connection string so that there will be no .mdf file.
Is the following connectionString correct?
<connectionStrings>
<!--<add name="conString" connectionString="metadata=res://*/conString.csdl|res://*/conString.ssdl|res://*/conString.msl;provider=System.Data.SqlClient;provider connection string="Data Source=.\SQL2008;AttachDbFilename=|DataDirectory|\NData.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;MultipleActiveResultSets=True"" providerName="System.Data.EntityClient" />-->
<add name="conString" connectionString="metadata=res://*/conString.csdl|res://*/conString.ssdl|res://*/conString.msl;provider=System.Data.SqlClient;provider connection string="Data Source=.\SQL2008;Initial Catalog=NData;Integrated Security=True;Connect Timeout=30;User Instance=True;MultipleActiveResultSets=True"" providerName="System.Data.EntityClient" />
Because I always get the error:
The underlying provider failed on Open
I had this error and found a few solutions:
Looking at your connection string, it looks valid. I found this blog post, the problem here is that they were using Integrated Security. If you are running on IIS, your IIS user needs access to the database.
If you are using Entity Framework with Transactions, Entity Framework automatically opens and closes a connection with each database call. So when using transactions, you are attempting to spread a transaction out over multiple connections. This elevates to MSDTC.
(See this reference for more information.)
Changing my code to the following fixed it:
using (DatabaseEntities context = new DatabaseEntities())
{
context.Connection.Open();
// the rest
}
context.Connection.Open() didn't help solving my problem so I tried enabling "Allow Remote Clients" in DTC config, no more error.
In windows 7 you can open the DTC config by running dcomcnfg, Component Services -> Computers -> My Computer -> Distributed Transaction Coordinator -> Right click to Local DTC -> Security.
You should see innerException to see what the inner cause of throwing of
error is.
In my case, the original error was:
Unable to open the physical file "D:\Projects2\xCU\xCU\App_Data\xCUData_log.ldf". Operating system error 5: "5(Access is denied.)".
An attempt to attach an auto-named database for file D:\Projects2\xCU\xCU\App_Data\xCUData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
which solved by giving full permission to current user for accessing related mdf and ldf files using files' properties.
I found the problem was that I had the server path within the connection string in one of these variants:
SERVER\SQLEXPRESS
SERVER
When really I should have:
.\SQLEXPRESS
For some reason I got the error whenever it had difficulty locating the instance of SQL.
This is common issue only. Even I have faced this issue. On the development machine, configured with Windows authentication, it is worked perfectly:
<add name="ShoppingCartAdminEntities" connectionString="metadata=res://*/ShoppingCartAPIModel.csdl|res://*/ShoppingCartAPIModel.ssdl|res://*/ShoppingCartAPIModel.msl;provider=System.Data.SqlClient;provider connection string="data source=.\SQlExpress;initial catalog=ShoppingCartAdmin;Integrated Security=True;multipleactiveresultsets=True;application name=EntityFramework"" providerName="System.Data.EntityClient" />
Once hosted in IIS with the same configuration, I got this error:
The underlying provider failed on Open
It was solved changing connectionString in the configuration file:
<add name="MyEntities" connectionString="metadata=res://*/ShoppingCartAPIModel.csdl|res://*/ShoppingCartAPIModel.ssdl|res://*/ShoppingCartAPIModel.msl;provider=System.Data.SqlClient;provider connection string="data source=MACHINE_Name\SQlExpress;initial catalog=ShoppingCartAdmin;persist security info=True;user id=sa;password=notmyrealpassword;multipleactiveresultsets=True;application name=EntityFramework"" providerName="System.Data.EntityClient" />
Other common mistakes could be:
Database service could be stopped
Data Source attributes pointing to a local database with Windows authentication and hosted in IIS
Username and password could be wrong.
When you receive this exception, make sure to expand the detail and look at the inner exception details as it will provide details on why the login failed. In my case the connection string contained a user that did not have access to my database.
Regardless of whether you use Integrated Security (the context of the logged in Windows User) or an individual SQL account, make sure that the user has proper access under 'Security' for the database you are trying to access to prevent this issue.
The SQL Server Express service were not set tostart automatically.
1) Go to control panel
2) Administrative Tools
3) Service
4) Set SQL Server express to start automatically by clicking on it
5) Right click and start the service
I hope that will help.
I had a similar issue with the SQL Server Express Edition on Windows Server 2003. I simply added the network service as a user in the database security.
This can also happen if you restore a database and the user already exists with different schema, leaving you unable to assign the correct permissions.
To correct this run:
USE your_database
EXEC sp_change_users_login 'Auto_Fix', 'user', NULL, 'cf'
GO
EXEC sp_change_users_login 'update_one', 'user', 'user'
GO
I posted a similar issue here, working with a SQL 2012 db hosted on Amazon RDS. The problem was in the connection string - I had "Application Name" and "App" properties in there. Once I removed those, it worked.
Entity Framework 5 and Amazon RDS - "The underlying provider failed on Open."
Make sure that each element value in the connection string being supplied is correct. In my case, I was getting the same error because the name of the catalog (database name) specified in the connection string was incorrect.
I had a similar issue with exceptions due to the connection state, then I realized I had my domain service class variable marked as static (by mistake).
My guess is that once the service library is loaded into memory, each new call ends up using the same static variable value (domain service instance), causing conflicts via the connection state.
I think also that each client call resulted in a new thread, so multiple threads accessing the same domain service instance equated to a train wreck.
I had the same problem but what worked for me was removing this from the Connection String:
persist security info=True
I had a similar error with the inner exception as below:
operation is not valid for the state of the transaction
I could resolve it by enabling DTC security settings.
Go To Properties of DTC, under Security Tab, check the below
Network DTC Access
Allow RemoteClients
Transaction Manager Communication
Allow Inbound
Allow Outbound
If you happen to get this error on an ASP.NET web application, in addition to other things mentioned check the following:
Database User Security Permissions (which users are allowed access to your database.
Check your application pool in IIS and make sure it's the correct one that is allowed access to your database.
I got rid of this by resetting IIS, but still using Integrated Authentication in the connection string.
Defining a new Windows Firewall rule for SQL Server (and for port 1433) on the server machine solves this error (if your servername, user login name or password is not wrong in your connection string...).
NONE of the answers worked for me
I think that some of us all make silly mistakes, there are 100 ways to fail ...
My issue was new project, I setup all the configuration in another project, but the caller was a Web Api project in which I had to copy the same connection string in the Web api project.
I think this is crazy considering I was not even newing up dbcontext or anything from the web api.
Otherwise the class library was trying to look for a Database named
TokenApi.Core.CalContext
of which my project is named TokenApi.Core and the CalContext is the name of the connection string and the file name
I was searching all over the web for this problem. I had the wrong name in the connection string, please check you connection string in web.config. I had name="AppTest" but it should have been name="App".
In my AppTestContext.cs file I had:
public AppTestContext() : this("App") { }
Wrong connection string:
<add connectionString="Data Source=127.0.0.1;Initial Catalog=AppTest;Integrated Security=SSPI;MultipleActiveResultSets=True" name="AppTest" providerName="System.Data.SqlClient" />
Right connection string:
<add connectionString="Data Source=127.0.0.1;Initial Catalog=AppTest;Integrated Security=SSPI;MultipleActiveResultSets=True" name="App" providerName="System.Data.SqlClient" />
A common mistake that I did because I was moving application from once pc to another and none of the above worked was that I forgot to copy the connection string to both App.Config and Web.Config!
I had a similar problem: In my test-cases executions I always got this error. I found out, that my "Distributed Transaction Service" was not started (run: services.msc -> start "Distributed Transaction Service" (best to set it to start automatic)). After I did that, it worked like a charm...
I was also facing the same issue. Now I have done it by removing the user name and password from the connection string.
For me it was just a simple mistake:
I used Amazon EC2, and I used my elastic IP address in the connection string, but when I changed IP addresses I forgot to update my connection string.
I had this error suddenly happen out of the blue on one of our sites. In my case, it turned out that the SQL user's password had expired! Unticking the password expiration box in SQL Server Management Studio did the trick!
I had the same issue few days ago, using "Integrated Security=True;" in the connection string you need to run the application pool identity under "localsystem" Sure this is not recommended but for testing it does the job.
This is how you can change the identity in IIS 7:
http://www.iis.net/learn/manage/configuring-security/application-pool-identities
In IIS set the App Pool Identity As Service Account user or Administrator Account or ant account which has permission to do the operation on that DataBase.
In my case I had a mismatch between the connection string name I was registering in the context's constructor vs the name in my web.config. Simple mistake caused by copy and paste :D
public DataContext()
: base(nameOrConnectionString: "ConnStringName")
{
Database.SetInitializer<DataContext>(null);
}
I had this problem because the Application Pool login this app was running under had changed.
In IIS:
Find the Application pool by clicking on your site and going to Basic Settings.
Go to Application Pools.
Click on your site's application pool.
Click on Advanced Settings.
In Identity, enter account login and password.
Restart your site and try again.
I have solved this way.
Step 1:
Open Internet Information Service Manager
Step 2:
Click on Application Pools in left navigation tree.
Step 3:
Select your version Pool. In my case, I am using ASP .Net v4.0. If you dont have this version, select DefaultAppPool.
Step 4:
Right click on step 3, and select advanced settings.
Step 5:
Select Identity in properties window and click the button to change the value.
Step 6:
Select Local System in Built-in accounts combo box and click ok.
That's it. Now run your application. Everything works well.
Codeproject Solution : the-underlying-provider-failed-on-open
I get this error when call async EF method from sync Main console (await was skipped).
Because async opening a connection was for an already disposed data context.
Solve: call async EF methods correctly