I have created Generic Repository and I have two entities that i need to update in a transaction.
Here is what i m doing..
ProductOrganizationEntity poDataContext= new ProductOrganizationEntity();
IRepository<tblProductInfo> productRepo = new GenericRepository<ProductOrganizationEntity, tblConfirmation>(poDataContext);
Piece of Code which is causing problem is this.
using (TransactionScope txScope = new TransactionScope())
{
productRepo.Attach(productEntity);
productRepo.SaveChanges();
new ProductLocation().SaveLocation(productEntity.Locations, productEntity.productCode);
txScope.Complete();
}
productRepo.SaveChanges(); This is where it throws me Error. The error is
The operation could not be performed because OLE DB provider "SQLNCLI10" for linked server "Venus" was unable to begin a distributed transaction.
(We do have server named Venus but its not access in anyway in these transactions at all. Secondly as i said this works without transaction block).
This piece of code works fine if taken out from Transaction Block.
ProductLocation.SaveLocation is creating Repository for Location . Here is the code from Save Location.
IRepository<LocationInfo> locRepo= new GenericRepository<ProductOrganizationEntity, LocationInfo>(new ProductOrganizationEntity());
if (loc.locID <= 0) // This is a new Location to be added.
locRepo.Add(locEntity);
else
locRepo.Attach(siteToAdd);
locRepo.SaveChanges();
Here is what i have done in my generic repository for thse methods
public void Attach(TEntity entity)
{
if (entity == null)
throw new ArgumentException("Update : Supplied Entity is Null.");
_currentDbSet.Add(entity);
System.Data.Entity.Infrastructure.DbEntityEntry entry = _dataContext.Entry(entity);
entry.State = System.Data.EntityState.Modified;
}
and this is what i have in SaveChanges in my generic repo.
public virtual void SaveChanges()
{
if (_dataContext == null)
throw new Exception("SaveChanges: DataContext is not initialized.");
_dataContext.SaveChanges();
}
What is that i am doing wrong here .
I appreciate any pointers.
It might be possible that your server is linked to another SQL server at the database level.
Perhaps look at this: http://msdn.microsoft.com/en-us/library/ms188279.aspx
Must admit I've never used linked servers (not yet at least), but seeing "Linked Servers" in the error made me think of this.
Related
I have a weird problem with Entity Framework code first migrations. I've been using EF and code first migrations on a project for months now and things are working fine. I recently created a new migration and when running Update-Database a restored backup of my database I get this error:
The model backing the context has changed since the database was
created. Consider using Code First Migrations to update the database
The migration does something like the following:
public override void Up()
{
using (SomeDbContext ctx = new SomeDbContext())
{
//loop through table and update rows
foreach (SomeTable table in ctx.SomeTables)
table.SomeField = DoSomeCalculation(table.SomeField);
ctx.SaveChanges();
}
}
I'm not using the Sql() function because DoSomeCalculation must be done in C# code.
Usually when I get something like this is means that I have updated my model somehow and forgot to create a migration. However that's not the case this time. The weird thing is that the error isn't even occurring on a migration that I created a few days ago and had been working fine.
I looked a quite a few articles about this and they all seems to say call
Database.SetInitializer<MyContext>(null);
Doing that does seem to work, but my understanding (based on this article) is that doing that will remove EF's ability to determine when the database and model are out of sync. I don't want to do that. I just want to know why it thinks they are out of sync all of a sudden.
I also tried running Add-Migration just to see if what it thought changed about the model but it won't let me do that stating that I have pending migrations to run. Nice catch 22, Microsoft.
Any guesses as to what's going on here?
I'm wondering if maybe the fact that migration listed above is using EntityFramework is the problem. Seems like maybe since it's not the latest migration anymore, when EF gets to it tries to create a SomeDbContext object it checks the database (which is not fully up to date yet since we're in the middle of running migrations) against my current code model and then throws the "context has changed" error.
It's possibly related to your using EF within the migration. I'm not sure how you're actually managing this, unless you've set a null database initialiser.
If you need to update data within a migration, use the Sql function, e.g.
Sql("UPDATE SomeTable SET SomeField = 'Blah'");
You should note that the Up() method is not actually running at the time of doing the migration, it's simply used to set up the migration which is then run later. So although you may think you've done something in the migration above the bit where you're using EF, in reality that won't have actually run yet.
If you cannot refactor your calculation code so it can be written in SQL, then you would need to use some mechanism other than migrations to run this change. One possibility would be to use the Seed method in your configuration, but you would need to be aware that this does not keep track of whether the change has been run or not. For example...
internal sealed class Configuration : DbMigrationsConfiguration<MyContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
protected override void Seed(MyContext context)
{
// Code here runs any time ANY migration is performed...
}
}
I tried replacing the EntityFramework code with regular ADO.NET code and it seems to work. Here is what it looks like:
public override void Up()
{
Dictionary<long, string> idToNewVal = new Dictionary<long, string>();
using (SqlConnection conn = new SqlConnection("..."))
{
conn.Open();
using (SqlCommand cmd = new SqlCommand("SELECT SomeID, SomeField FROM SomeTable", conn))
{
SqlDataReader reader = cmd.ExecuteReader();
//loop through all fields, calculating the new value and storing it with the row ID
while (reader.Read())
{
long id = Convert.ToInt64(reader["SomeID"]);
string initialValue = Convert.ToString(reader["SomeField"]);
idToNewVal[id] = DoSomeCalculation(initialValue);
}
}
}
//update each row with the new value
foreach (long id in idToNewVal.Keys)
{
string newVal = idToNewVal[id];
Sql(string.Format("UPDATE SomeTable SET SomeField = '{0}' WHERE SomeID = {1}", newVal, id));
}
}
I am trying to use Code First with Migrations. Even though there are no current changes to my model, I'm getting an exception. When I add a migration, the up and down are empty, but I get a runtime error with the message as follows:
An exception of type 'System.InvalidOperationException' occurred in
EntityFramework.dll but was not handled in user code
Additional information: The model backing the 'MyDataContext' context
has changed since the database was created. Consider using Code First
Migrations to update the database (http://go.microsoft.com/fwlink/?
My architecture is as follows:
DataAccess project that includes the context, fluid configurations and migrations code
Model project that contains the poco classes
Web API and MVC projects that each contain the connections string in their respective web.config files.
Additionally I have the following code:
DbInitializer
public static MyDataContext Create()
{
Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyDataAccess.MyDataContext, MyDataAccess.Migrations.Configuration>());
return new MyDataContext(ConfigurationManager.ConnectionStrings["MyDataContext"].ConnectionString, null);
}
I started with AutomaticMigrationsEnabled = false; in the migration Configuration constructor, as it was my understanding that this would allow (and require) me to have more control over when migrations were applied. I have also tried setting this to true but with the same result.
I added a new migration upon receiving this error, and the Up method was empty. I updated the database to this new migration, and a record was created in the _migrationHistory table, but I still receive the error when I attempt to run the application. Also, the seed data was not added to the database.
protected override void Seed(MyDataAccess.MyDataContext context)
{
IdentityResult ir;
var appDbContext = new ApplicationDbContext();
var roleManager = new RoleManager<IdentityRole>(new RoleStore<IdentityRole>(appDbContext));
ir = roleManager.Create(new IdentityRole("Admin"));
ir = roleManager.Create(new IdentityRole("Active"));
ir = roleManager.Create(new IdentityRole("InActive"));
var userNamager = new UserManager<User>(new UserStore<User>(appDbContext));
// assign default admin
var admin = new User { UserName = "administrator", Email = "myAdmin#gmail.com" };
ir = userNamager.Create(admin, "myp#55word");
ir = userNamager.AddToRole(admin.Id, "Admin");
}
where
public class ApplicationDbContext : IdentityDbContext<User>
{
public ApplicationDbContext()
: base("MyDataContext", throwIfV1Schema: false)
{
}
...
The question: If Add-Migration isn't seeing any change in the model, why do I get this error when I run? Why isn't the seed code being hit? How do I fix this, or if that can't be determined, how do I further determine the root cause?
I am not sure if you found the answer to your problem, but this other answer I found here actually did it for me:
Entity Framework model change error
I actually ended up deleting the __MigrationHistory table in SQL Server which I didn't know it was being created automatically.
The article also talks about the option to not generate it I think by using this instruction: Database.SetInitializer<MyDbContext>(null); but I have not used it, so I am not sure if it works like that
This worked for me.
Go to Package Manager Console and Run - Update-Database -force
I bet your data context is not hooking up the connection string.
Check if it's not initialized with a localdb (something like (localdb)\v11.0) and not working with that when you might think it's set to something else.
My issue ended up being a conflict between Automatic Migrations being enabled and the initializer MigrateDatabaseToLatestVersion as described here.
I am working with a database first model in Entity Framework 5 and when I attempt to add a row, I get the following error:
"No views were found in assemblies or could be generated for Table 'ui_renewals'."
The table exists in my EDMX and the template generated a ui_renewals class. I've deleted the table from the EDMX and added it again using the Update Model from Database option and I get the same error. Creating a separate connection for it resolves the issue, but that seems like a less-than-ideal solution (more like a kludge) not to mention it makes it more difficult to maintain in the future.
Any ideas on how to fix this so that I can add or update (I've tried both) a row in ui_renewals?
Here is the code I'm currently using - only difference before was using db as a DBContext instead of ui (yes, receipt is misspelled - gotta love legacy stuff)
[HttpPost]
public bool UpdateTeacher(string login_id, string password, UIRenewal data)
{
if (ModelState.IsValid)
{
// map from UIRenewal VM to ui_renewal
ui_renewals Renewal = Mapper.Map<UIRenewal, ui_renewals>(data);
// check to see if this is a new entry or not
var tmp = ui.ui_renewals.Find(Renewal.reciept);
if (tmp == null)
ui.ui_renewals.Add(Renewal);
else
{
// mark as modified
db.Entry(Renewal).State = EntityState.Modified;
}
// save it
try
{
ui.SaveChanges();
}
catch (DBConcurrencyException)
{
return false;
}
return true;
}
return false;
}
I should mention that I do have a view in the model (v_recent_license).
I know this is a very old question, however as I haven't found any other topics like this, I'll post my answer.
I have had the same Exception thrown. I found that, in a failed attempt to optimize EF performance, following the advices found here, I left behind this piece of code in EF .edmx code-behind:
<EntityContainerMapping StorageEntityContainer="XXXModelStoreContainer" CdmEntityContainer="YYYEntities" GenerateUpdateViews="false">
I removed the GenerateUpdateViews="false" string, and all is working again.
(The Exception message is a little misleading in my opinion).
I want to use TransactionScope class in my business layer to manage database operation in data access layer.
Here is my sample code. When i execute it, it tries to enable the dtc. I want to do the operation without enable dtc.
I already checked https://entlib.codeplex.com/discussions/32592 article. It didn't work for me. I read many articles on this subject but none of them really touch enterprise library or i didn't see.
by the way, i am able to use TransactionScope using dotnet sql client and it works pretty well.
what would be the inside of SampleInsert() method?
Thanks,
Business Layer method:
public void SampleInsert()
{
using (TransactionScope scope = new TransactionScope())
{
Sample1DAL dal1 = new Sample1DAL(null);
Sample2DAL dal2 = new Sample2DAL(null);
Sample3DAL dal3 = new Sample3DAL(null);
dal1.SampleInsert();
dal2.SampleInsert();
dal3.SampleInsert();
scope.Complete();
}
}
Data Access Layer method:
//sampleInsert method structurally same for each 3 dal
public void SampleInsert()
{
Database database = DatabaseFactory.CreateDatabase(Utility.DATABASE_INFO); ;
using (DbConnection conn = database.CreateConnection())
{
conn.Open();
DbCommand cmd = database.GetStoredProcCommand("P_TEST_INS", "some value3");
database.ExecuteNonQuery(cmd);
}
}
Hi yes this will enable dtc because you are creating 3 DB connections within one TransactionScope . When more than one DB connection is created within same TransactionScope the local transaction escalate to Distributed Transaction and hence dtc will be enabled to manage Distributed Trnsactions.You will have to do it in a way that only one DB connection is created for entire TransactionScope. I hope this will give you an idea.
After research and waching query analyzer, I changed the SampleInsert() body as follows and it worked. The problem was as ethicallogics mentioned opening new connection each time i access the database.
public void SampleInsert()
{
Database database = DatabaseFactory.CreateDatabase(Utility.DATABASE_INFO);
using (DbCommand cmd = database.GetStoredProcCommand("P_TEST_INS", "some value1"))
{
database.ExecuteNonQuery(cmd);
}
}
I'm working with an existing set of code that manages multiple database updates in a single transaction. Here is a simplified example:
Database db = DatabaseFactory.CreateDatabase();
using (DbConnection dbConnection = db.CreateConnection())
{
dbConnection.Open();
DbTransaction dbTransaction = dbConnection.BeginTransaction();
try
{
//do work
dbTransaction.Commit();
}
catch (Exception ex)
{
dbTransaction.Rollback();
}
}
I am also using EntityFramework in this same project for new development. Below is a simplified example of the usage of my repository class:
List<ThingViewModel> things = new List<ThingViewModel>();
// populate list of things
IObjectRepository thingRepository = new ThingRepository();
thingRepository.AddThings(things);
thingRepository.Save();
I want the work done in 'AddThings' to happen as part of the transaction in the first block of code.
Is there some clean way of blending my repository pattern into this existing code or vice-versa? I'm not at the point yet where it is feasible to rewrite the existing code to be entirely within EntityFramework, so I'm looking for some some interim approach.
I have tried passing the transaction from the older code into the repository, and thus EntityFramework, but that does not seem to work. I have also tried passing the ObjectContext back out to the older code in order to enlist it in the transaction. Neither approach works.
I cannot believe that I am the first person to encounter this hurdle in migrating existing code to EntityFramework... there must be something I am not considering.
I'll list the things that I have tried below:
using (TransactionScope transactionScope = new TransactionScope())
{
Database db = DatabaseFactory.CreateDatabase();
using (DbConnection dbConnection = db.CreateConnection())
{
dbConnection.Open();
DbTransaction dbTransaction = dbConnection.BeginTransaction();
try
{
//do work
dbTransaction.Commit();
}
catch (Exception ex)
{
dbTransaction.Rollback();
}
}
Thing thing = new Thing(){
Prop1 = Val1,
Prop2 = Val2
};
ThingObjectContext context = new ThingObjectContext();
context.Things.AddObject(thing);
context.SaveChanges();
transactionScope.Complete();
}
This last example 'works', it does not function as a transaction. When the EF insert fails, the EL commands are not rolled back by the TransactionScope. If I don't put those explicit calls to .Commit() and .SaveChanges(), nothing happens. I would really like for this to share the same connection if possible. Two other variations of this I am currently playing around with is trying to use the same connection between both EF and EL as well as use EnlistTransaction on one side or the other. Definitely trying to keep this from becoming a MSDTC - don't want the extra overhead associated with that.
Use TransactionScope instead of explicit transaction management. You'll simplify the overall code and everything you do should automatically detect and use the same transaction.
Is there any way you can call Database.GetOpenConnection() instead of CreateConnection() in your EL code, and pass in the things.Connection that you create inside of a TransactionScope block? I haven't tested this, but that is what I would try first.