I am currently working on an ASP.NET MVC project with Entity Framework. The solution includes the ASP.NET MVC application and a DataProvider project. The project only includes an EF model, as I have a partner who shares a database with me.
The problem is in that, that we don't actually share the same database. What I mean is that the actual server of the database is not the same. We have the same tables. But the connection string has to be changed every single time we pull from our git repository. The string changes in the web.config file of the ASP.NET MVC project and in the app.config file of the EF library.
My question is - if there is a way for our system to detect which PC it is running on and modify the connection string dynamically? Now I do it manually.
<!--PC NICO CEI-->
<!--
<connectionStrings>
<add name="dbShubertEntities"
connectionString="metadata=res://*/ModelDbShubert.csdl|res://*/ModelDbShubert.ssdl|res://*/ModelDbShubert.msl;provider=System.Data.SqlClient;provider connection string="data source=E04\SQLEXPRESS;initial catalog=dbShubert;user id=gereisma17;password=12321;MultipleActiveResultSets=True;App=EntityFramework""
providerName="System.Data.EntityClient" />
</connectionStrings>
-->
<!--PC NICO Laptop-->
<!--
<connectionStrings>
<add name="dbShubertEntities"
connectionString="metadata=res://*/ModelDbShubert.csdl|res://*/ModelDbShubert.ssdl|res://*/ModelDbShubert.msl;provider=System.Data.SqlClient;provider connection string="data source=DESKTOP-I62BLOC;initial catalog=dbShubert;user id=user;password=1234;MultipleActiveResultSets=True;App=EntityFramework""
providerName="System.Data.EntityClient" />
</connectionStrings>
-->
This is what I do now. I am commenting the connection string. I want to automate the whole thing.
You could overload the DbContext's constructor with the dynamic connection string
public class MasterDal : DbContext
{
public MasterDal(string nameOrConnectionString) : base(nameOrConnectionString)
{
}
// DbSet & OnModelCreating etc
}
& then invoke dal in Controller as required
if (logicToGetPc.equal("CEI"))
{
MasterDal dal = new MasterDal("dbShubertEntitiesCEI");
// do mumbai related whatever
}
else if (logicToGetPc.equal("Laptop"))
{
MasterDal dal = new MasterDal("dbShubertEntitiesCEILaptop");
}
if you are using aspnet core there is a way to configure environment variable as override for the app settings
this way you'll have a "default" appsettings.json that contains all the common settings, then on the different machine you can configure environmnet variables that replaces (override) the connection string in different way for each machine
i suppose a similar approach is possible for aspnet for the full framework as well
as your connection string have already a quite specific name "dbShubertEntities" it sould be quite effective to override and you should not risk to have connection string collisions in case you work on different projects.
as reference see https://joonasw.net/view/asp-net-core-1-configuration-deep-dive the part where it uses .AddEnvironmentVariables()
Store the connection string as an environment variable on each PC.
When creating the connection to the database, retrieve the connection string using Environment.GetEnvironmentVariable method instead.
(at time of writing, there's no code)
This is what appsettings.json, (or it's counterparts), was made for.
As i perceive your predicament, (you need more whitespace in your writing to make it easier to read), you are basically working in two different environments, (similar to dev versus test). A simple configuration change would be the simplest way.
As an aside:
Reading between the lines, it seems like you are hard-coding connection strings, and I have a two-word advice for you: STOP IT! (I used to do that, and It's a bad habit that can be hard to shake off)
I have developed a website application under visual studio using the MVC Pattern and Entity Framework 6.
This web app was linked to a local database.
I've published the application on my azure acc. I also exported the database on Azure following this tutorial.
However, I can't find a way to link the online app to the migrated database.
No data is displayed on the app and when I try to check for the connexion string I get an error , the connexion string hasn't been updated and therefore the app is still trying to target my local database.
I would like to know if anyone might know how to solve this.
EDIT : The problem may be somewhere else, I apparently have two connexions , one for my migrated DB and one for my local db. Perhaps I need to remove the connexion string targetting my local DB but I don't know how to do that
Also, since the Migrated database is a copy from the local one I was using before, do I need to change anything in my Model,views or controller ?
EDIT2 : Thanks to the comment below I was able to override the false Connexion String. However my datas are still not displayed on my application and I haven't found yet what could have happend.
I suspect that my model is still the same model as the one used by the local database as it has the same name. Does anybody know how to change the model to the current model of the online database ?
Thanks.
Because you created your app with entity framework there should be a connection string defined in the web.config file pointing to the local database.
<connectionStrings>
<add name="MyContext" connectionString="..."
providerName="System.Data.SqlClient" />
</connectionStrings>
If you have published your Website as WebApp (App Service) then you can change the connection string for the database under the Application Settings pane on the WebApp Page.
You can override your connection string by creating a connection string settings entry with the name of the connection string in the web.config file.
(For the snippet above - MyContext)
I am working with entity framework and azure, I got a WCF in a web role which uses methods from the project with entity framework..it seems that I am placing the connection string on the wrong file or that I am defining it wrongly.. it is as follows :
<connectionStrings>
<!-- Windows Azure SQL Database Connection String -->
<add name="AMTEntitiesContainer"
connectionString="here goes my connection string"
providerName="System.Data.EntityClient" />
</connectionStrings>
This is inside my app.config file in my entities library project..should it go to into the config of my webrole? or should it go into my WCF service ?
The connection string should be in the web.config of the WCF service. The EntityFramework project will be executed in-process. The WCF service is the process running.
This could be also helpful to understand these things.
I'm sorry for the post, I can not write comments yet.
If it is the WebService that interact with Azure, you need to move this into its Web.config. If it's the application you have another problem.
I had this,
Simply because I was creating my model incorrectly.
I was incorrectly doing:
var model = new ModelName;
Instead of correctly doing:
var model = ModelName.Create();
So this error may be thrown for a simple reason like that
I am successfully running tests through the the WCF Test Client, until I try to pull in data with Entity Framework.
To make sure I'm not doing anything stupid, I downloaded the sample code from this tutorial, which is doing something similar: http://www.codeproject.com/KB/WCF/WCFandEF.aspx
...and when I run it, I get the same error in a similar place:
var productEntity = (from p in context.ProductEntities
where p.ProductID == id
select p).FirstOrDefault();
The error is
The underlying provider failed on Open.
I can open the database fine from a "normal application" with the same connection string, it seems to be specific accessing the DB from the WCF test client.
Research here and on Google for "The underlying provider failed on Open." usual indicates that it's a connection string problem, but I'm pretty sure it's not in this case.
So now I expect it's some sort of permissions problem.
I am using SQL Server and Windows 7, with visual studio 2010.
I have been banging my head since yesterday, so any help or protective head gear appreciated.
Edited to include connection string
<add name="NorthwindEntities"
connectionString="metadata=res://*/Northwind.csdl|res://*/Northwind.ssdl|res://*/Northwind.msl;provider=System.Data.SqlClient;provider
connection string="Data Source=localhost;Initial Catalog=Northwind;User ID=sa;MultipleActiveResultSets=True""
providerName="System.Data.EntityClient" />
This error means 100% a problem in your connection string.
A good way to create a surely working connection string is to create a new(dummy) project, add an Entity Framework Data Model to it, select "Generate Model from Database", select your required connection, and click "Test Conntection" to be sure it works.
Make sure ""Save entity conection settings in App.Config as:..." is ticked.
Than, in you web/app.Config, you have a Connection String you can copy+paste to your own project
Have you tried inserting the database password into the connection string?
It worked for me.
Reference:
http://stack247.wordpress.com/2011/03/02/entity-framework-exception-the-underlying-provider-failed-on-open/
Well I had the same error for days... actualy for two days and Yes I found the solution Alhamdulillah..
As for me... I had Windows Authentication set on my Entity Service Connection.. So What I did was I went to IIS 7 Application Pool Advanced Settings for the web service... Changed the Identity from 'ApplicationPoolIdentity' to 'Network Service' and I setup my current user name and password as well.
I might face some other issues later on, still I would say a Good Start :-)!
I was remove "integrated security=True;" solved this way.
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