I am new to ASP.Net MVC . Any help is greatly appreciated in resolving my problem.
I am using a LINQToSQL db in my MVC application. For one of the auto generated partial class (Example MyClass assume for table MyClass) , I created another Partial class as MyClass and added DataAnnotations Like following...
namespcae NP
{
[MetadaType(typeof(myData))]
[Serializable()]
public partial class MyClass
{
}
public myData
{
[Required]
public string ID { get ; set ;}
// Other properties are listed here
}
}
In my controller class example MyHomeController
I have a code as follows:
List<MyClass> list = new List<MyClass>();
list = dbContext.StoredProcedure(null).ToList<MyClass>()
session["data"] = list.
above code works fine if I use inProc session state. But if I use SQLServer mode then I get error as
"Unable to serialize the session state. In 'StateServer' and
'SQLServer' mode, ASP.NET will serialize the session state objects,
and as a result non-serializable objects or MarshalByRef objects are
not permitted. The same restriction applies if similar serialization
is done by the custom session state store in 'Custom' mode. "
Can anyone tell me what I am doing wrong here..?. I can see the data is getting populated in ASPState database tables. By application throws error as follows.
Just mark as Serializable all classes whose instances you want to store in Session.
Finally I was able to resolve the issue.
Solution:
Add the below statement before querying the database. In my case I was calling LinqToSQl context( dbContext).
dbContext.ObjectTrackingEnabled = false;
Sample Code:
List empList = new List();
dbContext.ObjectTrackingEnabled = false;
empList = dbContext.SomeStoredProcedure().ToList()
Session["employee"] = empList.
Related
Working with database-first approach creating ASPNETCORE MVC web app with user authentication, I would like to override the way the parameters from IdentityUser class are queried to the database. The reason is the current implementation of IdentityUser has two new parameters NormalizedEmail and NormalizedUserName (which in my opinion retracts from Normalization).
Is there a way I can write the code below in the Model class so that those two parameters are not included in the query to the database or is that something that needs to be done in the controller class?
public class IdentityUser : Microsoft.AspNetCore.Identity.EntityFrameworkCore.IdentityUser
{
public override string NormalizedUserName
{ get { return null; } set { value = null; } }
public override string NormalizedEmail
{ get { return null; } set { value = null; } }
}
Not far as I can tell, both parameters are part of the data model and as explained in this Issue #351
About Identity 3.0:
...Instead we compute a normalized representation of the user name and we
store it in a separate column so that lookups by normalized user name
should now be sargable.
So in other words, if you "override the way the parameters from IdentityUser class are queried to the database" in essence you'll be doing exactly the opposite the class intends to do.
For the love of heaven and earth I really wish someone could help me out with this issue. It seems everyone has something to say about EF but nothing about Linq-to-SQL.
I am trying to grab some data from my table via a stored procedure, believe me, that's all.
I added the Linq-to-SQL model (LAMP.dbml)
added the stored procedure (getAffectedParcel) from the server explorer. getAffectedParcel takes 2 strings as parameters
Build the application.
Added a domain service class (LAMPService)
Selected the (LAMPDataContext) as the data context class (normally I would tick generate metadata, but since I am not working with tables it's not enabled for ticking)
Added the following function to the LAMPService.cs:
public IEnumerable < getAffectedParcelResult > GetTheAffectedParcels(String v, String vf)
{
return this.DataContext.getAffectedParcel(v, vf).AsEnumerable();
}
Added the following code to a Silverlight page in an attempt to consume the stored procedure:
LAMPContext db = new LAMPContext();
try
{
var q = db.GetTheAffectedParcels("18606004005", "").Value;
foreach (getAffectedParcelResult GAP in q)
{
MessageBox.Show(GAP.Owner);
}
}
catch (Exception ex)
{
MessageBox.Show (ex.Message.ToString());
}
Build and run application. An error occurs stating:
Object reference not set to an instance of an object.
I have tried ~1000,000 ways to see if this thing would work, but to no avail. Please don't tell me to use Entity Framework, I want to use Linq-to-SQL. Can someone (anyone) help me out here.
//houdini
Calling a stored procedure from the Silverlight client happens in the Async world. Let's consider an example from the AdventureWorks database...
Here's what the Domain Service method looks like. It is calling the EF on a stored procedure in the database called 'BillOfMaterials'.
public IQueryable<BillOfMaterial> GetBillOfMaterials()
{
return this.ObjectContext.BillOfMaterials;
}
Back on the client side, here is the code for setting up the call...
public GetSp()
{
InitializeComponent();
DomainService1 ds1 = new DomainService1();
var lo = ds1.Load(ds1.GetBillOfMaterialsQuery());
lo.Completed += LoCompleted;
}
First, the Domain Service is created, and then it is used to load the results of the stored procedure. In this particular case, the result of this is an instance of 'LoadOperation'. These things are async, so the LoadOperation needs to have a callback for when it is finished. The callback code looks like this...
public ObservableCollection<BillOfMaterial> MyList { get; set; }
void LoCompleted(object sender, EventArgs e)
{
LoadOperation lo = sender as LoadOperation;
if(lo!=null)
{
MyList = new ObservableCollection<BillOfMaterial>();
foreach(BillOfMaterial bi in lo.AllEntities)
{
MyList.Add(bi);
}
dataGrid1.ItemsSource = MyList;
}
}
In this method, the 'sender' is dereferenced into the LoadOperation instance, and then all the goodies from the database can be accessed. In this trivial example, a list is built and passed to DataGrid as the ItemsSource. It's good for understanding, but you would probably do something else in practice.
That should solve your problem. :)
The best advice I can give on Silverlight and RIA is never do ANYTHING on your own until you have tried it in AdventureWorks. You will just waste your time and beat your head against the wall.
Firstly, it seems like your DomainService code is written for Invoke() rather than Query(). You should use Query as it enables you to update data back to the server.
Solution: you should add a [Query] attribute to GetTheAffectedParcels on the domain service.
[Query]
public IQueryable<Parcel>
GetTheAffectedParcels(string ParcelNumber, string LotNumber)
{
// etc.
}
Secondly, RIA Services needs to know which is the primary key on the Parcel class.
Solution: Apply a MetadataType attribute to the Parcel class, which allows you to add metadata to the Parcel class indirectly, since it is generated by Linq2Sql and you couldn't add annotations directly to the ParcelId - it'd get wiped away.
[MetadataType(typeof(ParcelMetadata)]
public partial class Parcel
{
}
public class ParcelMetadata
{
[System.ComponentModel.DataAnnotations.Key]
public int ParcelId {get; set; }
}
Thirdly, modify your client like this. Instead try this on the Silverlight client:
LAMPContext db = new LAMPContext();
try
{
var q = db.GetTheAffectedParcelsQuery("18606004005", "");
db.Load(q, (op) =>
{
if (op.HasError)
{
label1.Text = op.Error.Message;
op.MarkErrorAsHandled();
}
else
{
foreach (var parcel in op.Entities)
{
// your code here
}
}
}
}
catch (Exception ex)
{
label1.Text = op.ex.Message;
}
Much thanks to Chui and Garry who practically kicked me in the right direction :) [thanks guys...ouch]
This is the procedure I finally undertook:
-After adding the data model(LINQ2SQL) and the domain service, I created a partial class [as suggested by Chui] and included the following metadata info therein:
[MetadataTypeAttribute(typeof(getAffectedParcelResult.getAffectedParcelResultMetadata))]
public partial class getAffectedParcelResult
{
internal sealed class getAffectedParcelResultMetadata
{
[Key]
public string PENumber { get; set; }
}
}
Then, Adjusted the Domain Service to include the following:
[Query]
public IQueryable<getAffectedParcelResult> GetTheAffectedParcels(string v, string vf)
{
// IEnumerable<getAffectedParcelResult> ap = this.DataContext.getAffectedParcel(v, vf);
return this.DataContext.getAffectedParcel(v, vf).AsQueryable();
}
Then Build the app, afterwhich the getAffectedParcelResult store procedure appeared in the Data Sources panel. I wanted to access this via code however. Therefore, I accessed it in silverlight [.xaml page] via the following:
LAMPContext db = new LAMPContext();
var q = db.GetTheAffectedParcelsQuery("18606004005", "");
db.Load(q, (op) =>
{
if (op.HasError)
{
MessageBox.Show(op.Error.Message);
op.MarkErrorAsHandled();
}
else
{
foreach (getAffectedParcelResult gap in op.Entities)
{
ownerTextBlock.Text = gap.Owner.ToString();
}
}
},false);
This worked nicely. The thing is, my stored procedure returns a complex type so to speak. As of such, it was not possible to map it to any particular entity.
Oh and by the way this article helped out as well:
http://onmick.com/Home/tabid/154/articleType/ArticleView/articleId/2/Pulling-Data-from-Stored-Procedures-in-WCF-RIA-Services-for-Silverlight.aspx
I'm using a loosely coupled model between my Silverlight client and my DomainService.
I'm using POCO with EF 4.1
I'm not using any of the scaffolding the tooling offers.
The DomainService class is declared as:
public partial class MyDomainService : DbDomainService<MyContext>
{
...
}
in the update method I have the following:
public UpdatePerson(PersonInfo source)
{
var person = DbContext.People.Find(source.Id);
person.Name = source.Name;
DbContext.SaveChanges();
}
But when I manually check the database the change is not saved. However if I modify the code to look like this --- all is fine:
public UpdatePerson(PersonInfo source)
{
using(var context = GetDbContext())
{
var person = context.People.Find(source.Id);
person.Name = source.Name;
context.SaveChanges();
}
}
I suppose I don't mind creating my own local context variable, but I'm curious what's going on under the covers that the first approach doesn't work.
Since you are not using the DomainService the way that it is designed to work you may find it doing several weird things. DbContext.SaveChanges is never supposed to be called by your code, it will get called by the DomainService in the PersistChangeset method after all of the CUD methods in the changeset have been processed.
The DbContext held by the DomainService has several properties changed. ProxyCreationEnabled, ValidateOnSaveEnabled, AutoDetectChangesEnabled, and LazyLoadingEnabled are all set to false. In your case, since AutoDetectChangesEnabled is set to false just changing the person.Name will not trigger the DbContext to know that there are any changes to person.Name.
How do I handle situations in which I need pre-existing data before the app is started or right after the database is generated. For example, I have a list of countries in which I'd like to load into the database after code-first generates it. How do I do this?
App is structured as follows:
Repository > Service > WebMVC
The xml is in the WebMVC project.
You create custom initializer, which inherits from DropCreateDatabaseIfModelChanges or DropCreateDatabaseAlways interface. Like:
public class EntitiesContextInitializer : DropCreateDatabaseIfModelChanges<-YourDbContext->
And then you overwrite Seed method like:
protected override void Seed(YourDbContext context)
Whole example might look like:
public class EntitiesContextInitializer : DropCreateDatabaseIfModelChanges<EntitiesContext>
{
protected override void Seed(EntitiesContext context)
{
List<Role> roles = new List<Role>
{
new Role {Id=1, Title="Admin"},
new Role {Id=2, Title="ProjectManager"},
new Role {Id=3, Title="Developer"}
};
// add data into context and save to db
foreach (Role r in roles)
{
context.Roles.Add(r);
}
context.SaveChanges();
}
}
Edit: After setting this up, you have to set up Initializer too, as Ladislav Mrnka mentioned.
Database.SetInitializer(new EntitiesContextInitializer());
ie.: in Global.asax:
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
Database.SetInitializer(new EntitiesContextInitializer());
}
Don't forget to add using System.Data.Entity;
.....
You must create custom database initializer derived for example from DropCreateDatabaseIfModelChanges and fill data in overriden Seed method. Then you must use Database.SetInitializer to set your new initializer when application starts. Here is example (from CTP5) used to create custom index in the database.
For an example see the new MVC / Entity Framework tutorial series at
http://www.asp.net/entity-framework/tutorials#Using%20MVC
Both #1 and #4 show initializer classes.
I'm using nHibernate to update 2 columns in a table that has 3 encrypted triggers on it. The triggers are not owned by me and I can not make changes to them, so unfortunately I can't SET NOCOUNT ON inside of them.
Is there another way to get around the TooManyRowsAffectedException that is thrown on commit?
Update 1
So far only way I've gotten around the issue is to step around the .Save routine with
var query = session.CreateSQLQuery("update Orders set Notes = :Notes, Status = :Status where OrderId = :Order");
query.SetString("Notes", orderHeader.Notes);
query.SetString("Status", orderHeader.OrderStatus);
query.SetInt32("Order", orderHeader.OrderHeaderId);
query.ExecuteUpdate();
It feels dirty and is not easily to extend, but it doesn't crater.
We had the same problem with a 3rd party Sybase database. Fortunately, after some digging into the NHibernate code and brief discussion with the developers, it seems that there is a straightforward solution that doesn't require changes to NHibernate. The solution is given by Fabio Maulo in this thread in the NHibernate developer group.
To implement this for Sybase we created our own implementation of IBatcherFactory, inherited from NonBatchingBatcher and overrode the AddToBatch() method to remove the call to VerifyOutcomeNonBatched() on the provided IExpectation object:
public class NonVerifyingBatcherFactory : IBatcherFactory
{
public virtual IBatcher CreateBatcher(ConnectionManager connectionManager, IInterceptor interceptor)
{
return new NonBatchingBatcherWithoutVerification(connectionManager, interceptor);
}
}
public class NonBatchingBatcherWithoutVerification : NonBatchingBatcher
{
public NonBatchingBatcherWithoutVerification(ConnectionManager connectionManager, IInterceptor interceptor) : base(connectionManager, interceptor)
{}
public override void AddToBatch(IExpectation expectation)
{
IDbCommand cmd = CurrentCommand;
ExecuteNonQuery(cmd);
// Removed the following line
//expectation.VerifyOutcomeNonBatched(rowCount, cmd);
}
}
To do the same for SQL Server you would need to inherit from SqlClientBatchingBatcher, override DoExectuteBatch() and remove the call to VerifyOutcomeBatched() from the Expectations object:
public class NonBatchingBatcherWithoutVerification : SqlClientBatchingBatcher
{
public NonBatchingBatcherWithoutVerification(ConnectionManager connectionManager, IInterceptor interceptor) : base(connectionManager, interceptor)
{}
protected override void DoExecuteBatch(IDbCommand ps)
{
log.DebugFormat("Executing batch");
CheckReaders();
Prepare(currentBatch.BatchCommand);
if (Factory.Settings.SqlStatementLogger.IsDebugEnabled)
{
Factory.Settings.SqlStatementLogger.LogBatchCommand(currentBatchCommandsLog.ToString());
currentBatchCommandsLog = new StringBuilder().AppendLine("Batch commands:");
}
int rowsAffected = currentBatch.ExecuteNonQuery();
// Removed the following line
//Expectations.VerifyOutcomeBatched(totalExpectedRowsAffected, rowsAffected);
currentBatch.Dispose();
totalExpectedRowsAffected = 0;
currentBatch = new SqlClientSqlCommandSet();
}
}
Now you need to inject your new classes into NHibernate. There are at two ways to do this that I am aware of:
Provide the name of your IBatcherFactory implementation in the adonet.factory_class configuration property
Create a custom driver that implements the IEmbeddedBatcherFactoryProvider interface
Given that we already had a custom driver in our project to work around Sybase 12 ANSI string problems it was a straightforward change to implement the interface as follows:
public class DriverWithCustomBatcherFactory : SybaseAdoNet12ClientDriver, IEmbeddedBatcherFactoryProvider
{
public Type BatcherFactoryClass
{
get { return typeof(NonVerifyingBatcherFactory); }
}
//...other driver code for our project...
}
The driver can be configured by providing the driver name using the connection.driver_class configuration property. We wanted to use Fluent NHibernate and it can be done using Fluent as follows:
public class SybaseConfiguration : PersistenceConfiguration<SybaseConfiguration, SybaseConnectionStringBuilder>
{
SybaseConfiguration()
{
Driver<DriverWithCustomBatcherFactory>();
AdoNetBatchSize(1); // This is required to use our new batcher
}
/// <summary>
/// The dialect to use
/// </summary>
public static SybaseConfiguration SybaseDialect
{
get
{
return new SybaseConfiguration()
.Dialect<SybaseAdoNet12Dialect>();
}
}
}
and when creating the session factory we use this new class as follows:
var sf = Fluently.Configure()
.Database(SybaseConfiguration.SybaseDialect.ConnectionString(_connectionString))
.Mappings(m => m.FluentMappings.AddFromAssemblyOf<MyEntity>())
.BuildSessionFactory();
Finally you need to set the adonet.batch_size property to 1 to ensure that your new batcher class is used. In Fluent NHibernate this is done using the AdoNetBatchSize() method in a class that inherits from PersistenceConfiguration (see the SybaseConfiguration class constructor above for an example of this).
er... you might be able to decrypt them...
Edit: if you can't change code, decrypt, or disable then you have no code options on the SQL Server side.
However, You could try "disallow results from triggers Option" which is OK for SQL 2005 and SQL 2008 but will be removed in later versions. I don't know if it suppresses rowcount messages though.
Setting the "Disallow Results from Triggers" option to 1 worked for us (the default is 0).
Note that this option will not be available in a future releases of Microsoft SQL Server, but after it is no longer available it will behave as if it was set to 1. So setting this to 1 now fixes the problem and also give you the same behavior as will be in future releases.