I am creating 2 projects that have the same database (it's an MDF database). The first one is the map editor, and I use XNA 4 and Web Services to connect to it. The second one is the game itself and uses XNA 3.1 and Entity Data Model to connect database.
When I run the map editor and access the database, it runs properly. Bbut when I run the game and access the database, it shows an error "The underlying provider failed on Open"
I think the connection from the web service is not closed yet. But I don't know where I should close the connection.
Here is my code from the web service:
public Map AddNewMap(string username, string mapName, int sizeX, int sizeY)
{
using (BaseModelDataContext context = new BaseModelDataContext())
{
Map newMap = new Map()
{
Username = username,
Name = mapName,
SizeX = sizeX,
SizeY = sizeY,
Upload_Date = DateTime.Now,
Status = 0
};
context.Maps.InsertOnSubmit(newMap);
context.SubmitChanges(System.Data.Linq.ConflictMode.FailOnFirstConflict);
context.Dispose();
return newMap;
}
}
EDIT:
Here is the entity data model code :
using (MazeEntities ent = new MazeEntities())
{
ent.Connection.Open();
return (from map in ent.Map
select map).ToList<Map>();
}
This code runs properly if I did not use the web service before. If I use the web service first, it shows an error at ent.Connection.Open();
Here is the inner exception:
Cannot open user default database. Login failed.\r\nLogin failed for user 'erkape-PC\erkape'.
Connection string for web service :
connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\3DMapDatabase.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"
Connection string for the game:
"metadata=res:///MazeDataModel.csdl|res:///MazeDataModel.ssdl|res://*/MazeDataModel.msl;provider=System.Data.SqlClient;provider connection string="Data Source=.\SQLEXPRESS;AttachDbFilename=D:\eRKaPe\DropBox\TA\Program\3D_Map_Editor\3DMapEditorServices\App_Data\3DMapDatabase.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;MultipleActiveResultSets=True"" providerName="System.Data.EntityClient" />
For a quick check, can you try adding the following line after the using:
using (BaseModelDataContext context = new BaseModelDataContext())
{
context.Connection.Open();
OR
context.Database.Connection.Open();
// your code here
Finally I found a way to solve my problem after reading some articles.
The connection from the web service doesn't close automatically after I close the map editor. That is why I can't access my database from the game.
I have to change the connection string from both application, I set the User Instance to False. The game can access the database this way.
Please check the following post
http://th2tran.blogspot.ae/2009/06/underlying-provider-failed-on-open.html
Also please Enable for 32 Bit application in the APplication Pool of that application.
This may resolve.
You are trying to return an object (Map) which is associated with the Context. This object has the context information which can't be returned to the client.
You will need to create your own DataContract (a type having necessary properties) that you want to expose to the client.
Or you can use the POCO implementation As described here
Related
I have a C# .Net Web API deployed to an Azure App Service, I also have an Azure SQL Database.
In the API I am using Entity Framework to insert into the database, but I keep getting the error message: "The underlying provider failed on open".
(When running the API locally (in debug mode) connecting to a local database it works fine).
Could this be a permissions/firewall configuration problem with the Azure database, or something else?
I have added my current IP address in the "Azure Set Server Firewall", do I need to add the Azure Web API's IP address to the database firewall settings?
This is my API:
public class ProfileController : ApiController
{
[EnableCors(origins: "*", headers: "*", methods: "*")]
[WebMethod]
[HttpPost]
public HttpResponseMessage PostProfile([FromBody] Profile details)
{
var context = new XXXDBEntities();
var query = from c in context.Users
where c.Email.Equals(details.email, StringComparison.CurrentCultureIgnoreCase)
select c;
var emailFound = query.Count();
if (emailFound != 0)
{
return Request.CreateResponse(HttpStatusCode.OK, "There is already an account associated with this email address");
}
else
{
Guid token = Guid.NewGuid();
Users newRow = new Users();
newRow.Token = token;
newRow.FirstName = details.firstName;
newRow.LastName = details.lastName;
newRow.Email = details.email;
newRow.Password = details.password;
context.Users.Add(newRow);
context.SaveChanges();
return Request.CreateResponse(HttpStatusCode.OK, token);
}
}
This is my connection string:
This is the default format for connection strings in .Net Entity Framework, I have only added username, password and changed the data source and catalog fields. Is this correct?
<add name="XXXDBEntities" connectionString="metadata=res://*/XXXDB.csdl|res://*/XXXDB.ssdl|res://*/XXXDB.msl;provider=System.Data.SqlClient;provider connection string="data source=tcp:XXX.database.windows.net,1433;initial catalog=XXXDB;integrated security=True;User ID=XXXXX;Password=XXXXX;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
I have checked your connection string, it seems to be right. So I think your issue may be caused by the model of the SQL Azure is changed, but your project does not update it. Here is the same issue I reproduced on my side:
I would suggest you update your model.
do I need to add the Azure Web API's IP address to the database firewall settings?
We can set Allow access to Azure services as ON in SQL Azure firewall settings. So that we need not to add Azure web API's address.
You need to remove Integrated Security=True from the connection string since you are specifying a username and password.
I have a web app and a batch pool.
In the batch pool, created tasks are using the same database as the web app.
Today I started receiving the following exception in the batch:
A transport-level error has occurred when receiving results from the server. (provider: Session Provider, error: 19 - Physical connection is not usable)
The code base has not changed, older versions do not work, there were no updates, it just popped out of the blue. I repeated a couple tasks in a controlled debug environment in VS and they went through without any exceptions thrown. I went in and added the batch node’s IP to the sql server firewall rules, also no result. Meanwhile, the web application uses the database just fine.
Both the web app and batch pool are located in East US.
Here’s a snippet from Program.cs in my batch task:
MyEntities db; //MyEntities extends DbContext
System.Data.Entity.Core.EntityClient.EntityConnectionStringBuilder connstr = new System.Data.Entity.Core.EntityClient.EntityConnectionStringBuilder();
connstr.ProviderConnectionString = connectionString;
connstr.Provider = "System.Data.SqlClient";
connstr.Metadata = "res://*/MyEntities.csdl|res://*/MyEntities.ssdl|res://*/MyEntities.msl";
try {
db = new PepeEntities(connstr.ConnectionString);
}
The connection string looks like this:
Persist Security Info=True; Data Source=<host>; Initial Catalog=<database name>; Integrated Security=False; User ID=<login>; Password=<password>; MultipleActiveResultSets=True; Connect Timeout=30; Encrypt=True;
Edit:
This problem has subsided the same way it appeared: out of the blue. I’ll carry out tests whenever it surfaces again.
You can try one of these 2 possibilities:
1. Enabling an Execution Strategy:
public class MyEntitiesConfiguration : DbConfiguration
{
public MyEntitiesConfiguration()
{
SetExecutionStrategy("System.Data.SqlClient", () => new SqlAzureExecutionStrategy());
}
}
# please view more details here:https://msdn.microsoft.com/en-US/data/dn456835
2. if you have explicitly opened the connection, ensure that you close it. You can use an using statement:
using(var db = new PepeEntities(connstr.ConnectionString){
..do your work
}
https://blogs.msdn.microsoft.com/appfabriccat/2010/12/10/sql-azure-and-entity-framework-connection-fault-handling/
I have decided to start programming in ASP.NET MVC using C#
I have been following tutorials and implementing them into my own project.
What happens is that once i click Debug in Chrome/Firefox etc my database connection closes (the red cross appears)! (But when I refresh it manually it has the tick - till that point) I have a feeling it's to do with the connectionString in web.config. I don't like connection strings, to me they seem full of jargon. How many parameters do you REALLY need for a test project?
<connectionStrings>
<add name="PetsDBEntities" connectionString="metadata=res://*/MainDBModel.csdl|res://*/MainDBModel.ssdl|res://*/MainDBModel.msl;provider=System.Data.SqlClient;provider connection string="data source=(LocalDB)\v11.0;attachdbfilename=|DataDirectory|E:\Visual Studio 2013\Projects\Pets\Pets\App_Data\PetsDB.mdf;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework""
providerName="System.Data.EntityClient" />
</connectionStrings>
Unfortunately my knowledge of c#/asp.net mvc is VERY limited, hence following a tutorial but I know you guys at SO are really good at what you do.
The database named PetsDBEntities has the following properties.
Data Source: Microsoft SQL Server Database File (SQL Client)
Database File Name: projects/app_data/PetsDB.mdf
If i right click the database and click >Modify Connection and then click test connection I get a "This connection cannot be tested because the specified database file does not exist"
This is where the code breaks. NOTE: The values being submitted are passed through, it just seems that it is unable to connect and add the row to the database.
if (ModelState.IsValid)
{
using( var db = new PetsDBEntities())
{
var crypto = new SimpleCrypto.PBKDF2();
var encrpPass = crypto.Compute(user.Password);
var regUser = db.Users.Create();
regUser.Email = user.Email;
regUser.Password = encrpPass;
regUser.PasswordSalt = crypto.Salt;
regUser.UserID = Guid.NewGuid();
db.Users.Add(regUser);
db.SaveChanges(); //--------THIS IS WHERE I GET AN ERROR---------
return RedirectToAction("Index", "Pictures");
}
}
else
{
ModelState.AddModelError("", "Login Data is incorrect!");
}
return View();
Hopefully this is enough information for you guys to spot where the problem is.
Thansk for anyone that can help! Again, I am new and not entirely sure what information is completely needed.
Your issue is likely with the db filename.
attachdbfilename=|DataDirectory|E:\Visual Studio 2013\Projects\Pets\Pets\App_Data\PetsDB.mdf;
Should be:
attachdbfilename=|DataDirectory|\PetsDB.mdf;
Maybe this can help?
A simple connection string for SQL Server could be Server=myServerAddress;Database=myDataBase;User Id=myUsername;
Password=myPassword;
You mentioned that when you click on test connection, you are getting an error. Your question title might be misleading, as i can assume that you didn't established the connection at all.
Can you go to "Server Explorer" -> "Data Connections" -> "Add Connection" -> "Microsoft SQL Server Database File", i assume you are using the .mdf file directly instead of connecting to SQL server?
Click on "Test Connection" and if everything goes well, you can retrieve the connectionstring from the properties.
I'm using the entity framework in a winforms application.
When i set scsb.DataSource ="localhost" every thing works fine but when i try to connect to onother DB server i got an exception:
"The underlying provider failed on Open."
public DistributionSSEntities1 Connection()
{
var scsb = new SqlConnectionStringBuilder();
scsb.DataSource = "192.168.1.100";
scsb.InitialCatalog = "DistributionSS";
scsb.IntegratedSecurity = true;
//------------------------
EntityConnectionStringBuilder builder = new EntityConnectionStringBuilder();
builder.Metadata ="res://*/Model.Model.csdl|res://*/Model.Model.ssdl|res://*/Model.Model.msl";
builder.Provider = "System.Data.SqlClient";
builder.ProviderConnectionString = scsb.ConnectionString;
DistributionSSEntities1 db = new DistributionSSEntities1(builder.ToString());
return db;
}
Has the remote Sql been setup to allow remote connections? Has the remote Sql been allowed access through the windows firewall... there's so many reasons why it wouldn't connect.
You're using Integrated Security - which may work great for a local Sql; but the network user that your WinForm app is running under must have the correct rights to access the remote box.
I'd suggest to start eliminating possibilities do the following:
Check the Sql logs on the target server. That always has the exact reason why an attemp failed - not the watered down version you get through the exception. (eg. C:\Program Files\Microsoft SQL Server\MSSQL11.SQLEXPRESS\MSSQL\Log)
Connect to it using a sql username password - not integrated security to make sure it's not that
Firewall
EDIT
It's important to remember that the error messages return to the client regarding login attempt failures are purposefully obscure or without information - to limit an attacker gaining enough information to improve the attack (see the technet article for proof). So checking the Sql Server logs is a necessity - if your login/connection attempt actually made it to the server.
From Article:
To increase security, the error message that is returned to the client
deliberately hides the nature of the authentication error. However, in
the SQL Server error log, a corresponding error contains an error
state that maps to an authentication failure condition. Compare the
error state to the following list to determine the reason for the
login failure.
public DistributionSSEntities Connection()
{
string ConString = "SERVER=192.168.1.100;DATABASE=DistributionSS;UID=sa;PASSWORD=125;";
SqlConnectionStringBuilder SCB= new SqlConnectionStringBuilder(ConString);
//------------------------
EntityConnectionStringBuilder builder = new EntityConnectionStringBuilder();
builder.Metadata = "res://*/Model.Model.csdl|res://*/Model.Model.ssdl|res://*/Model.Model.msl";
builder.Provider = "System.Data.SqlClient";
builder.ProviderConnectionString = SCB.ConnectionString;
DistributionSSEntities db = new DistributionSSEntities(builder.ToString());
return db;
}
I have a situation when some clients see the server by its local IP and some by global. So that for some of them IP is 10.0.0.4 and for some 94.44.224.132. I use ClickOnce for deployment and Entity Framework to generate the DB mapping. Now ive connection string setting in my user settings section and for each user i store his own one. After that for entity context's construction i do the following:
SomeEntities context = new SomeEntities(new EntityConnection("metadata=res://*/DBModel.csdl|res://*/DBModel.ssdl|res://*/DBModel.msl;provider=System.Data.SqlClient;provider connection string=\"" + Properties.Settings.Default.ServerLocalConnectionString + "\""));
But there are some problems with Open/Close and Command execution after such approach. Is there some right way to store individual connection strings for every client and not overwrite them with deployment(ClickOnce is preferable)?
Found answer here.
EntityConnectionStringBuilder ecb = new EntityConnectionStringBuilder();
if (serverName=="Local")
{
ecb.ProviderConnectionString = Properties.Settings.Default.ServerLocalConnectionString;
}
else
{
ecb.ProviderConnectionString = Properties.Settings.Default.ServerConnectionString;
}
ecb.Metadata = "res://*/";
ecb.Provider = "System.Data.SqlClient";
SomeEntities context = new SomeEntities(new EntityConnection(ecb.ToString());
It seems this works. And now i can deploy the application and leave to the user the decision to which server does he want to connect and leave that configuration after updates, because its written in user's app.config.