Ok, I want to recreate a project that I created using EF 4.1 to EF 5.0, simple enough or at least I thought. One of the things in my old project is that I was able to change the database connection string at runtime in EF 4.1:
using (var myContext = new MyEntities(ConnectionString))
{
}
Easy-peasy but in EF 5.0 you have to do this differently:
string connectionString = "data source=LocalHost;initial catalog=MyDatabase;user id=MyUserName;password=MyPassword;multipleactiveresultsets=True;App=EntityFramework";
using (var myContext = new MyEntities())
{
myContext.Database.Connection.ConnectionString = connectionString;
}
Now, this took me a better part of two hours to figure out, so I guess my question is this the proper way of changing the connection string at runtime or not? If it is why did they make this change?
I did find this Link but it didn't work. I received the error as detailed in the first comment of the first answer by Ladislav Mrnka. I later found this Link which seems to work fine.
UPDATE
I re-read the first link I posted and I found another solution, I simply created a partial class:
public partial class MyEntities : DbContext
{
public MyEntities(string connectionString) : base(connectionString)
{
Database.Connection.ConnectionString = connectionString;
}
}
Use the context constructor overload that takes the connection string as a parameter.
Create a class with the same name as the Target ContextClass class next to the main class
like this :
public CustomerContext( string connectionString)
: base(connectionString)
{
}
For using :
using (var context = new CustomerContext("connectionString"))
{
}
Or
var customerContext=new CustomerContext("yorConnectionString");
var customer=CustomerContext.customer.FirstOrDefault(x=>x.id==1).FirstName;
Have a look at other link Setup Entity Framework For Dynamic Connection String.
It says - " you can do it by creating another partial class as the Entities class is declared partial"
Related
I'm using the in memory database provider for integration tests however I don't seem to be able to update a record. I've run the same code against a real SQL database and everything gets updated fine. Here is my test fixture code.
Test Fixture:
public class TestFixture<TStartup> : IDisposable
{
private readonly TestServer _testServer;
public HttpClient TestClient { get; }
public IDatabaseService DbContext { get { return _testServer.Host.Services.GetService<DatabaseService>(); } }
public TestFixture() : this(Path.Combine("src")) { }
protected TestFixture(string relativeTargetProjectPatentDir)
{
Environment.SetEnvironmentVariable("ASPNETCORE_ENVIRONMENT", "Testing");
var builder = new WebHostBuilder()
.ConfigureServices(services =>
{
services.AddDbContext<DatabaseService>(options =>
options.UseInMemoryDatabase("TestDB")
.EnableSensitiveDataLogging());
})
.UseEnvironment("Testing")
.UseStartup<Startup>();
_testServer = new TestServer(builder)
{
BaseAddress = new Uri("http://localhost:5010")
};
TestClient = _testServer.CreateClient();
TestClient.BaseAddress = _testServer.BaseAddress;
}
public void Dispose()
{
TestClient.Dispose();
_testServer.Dispose();
}
}
I've spent most of the day googling this and not come across any other people talking about it so I'm assuming its probably my issue rather than a EF bug. I'm sure someone would have noticed a DB that you can't update.
Updating works with Singleton but I have CQRS architecture and to check if the entry was updated in e2e test I have to reload entry
Context.Entry(entity).Reload();
I hope that this can help someone
It turned out that changing the lifetime of my DbContext in my test fixture to singleton solved my issue.
Well it can be that DbContext is used in wrong way. I had the same problem. I used the DbContext in same way as you. I simply returned the instance by .Host.Services.GetService<TContext>. The problem with this approach is that DbContext will never release tracked entities so either you set entity State as EntityState.Detached and you force DbContext to reload it, or you will use scopes.
using (var scope = _testServer.Host.Services.GetRequiredService<IServiceScopeFactory>().CreateScope())
{
var dbContext = scope.ServiceProvider.GetRequiredService<DatabaseService>();
//make any operations on dbContext only in scope
}
Adding to Chris's answer. Here is an example of what I had vs. what fixed the issue:
services.AddDbContext<TestDbContext>(options => {
options.UseInMemoryDatabase("TestDb");
});
to
var options = new DbContextOptionsBuilder<TestDbContext>()
.UseInMemoryDatabase(databaseName: "TestDb")
.Options;
services.AddSingleton(x => new TestDbContext(options));
Using AsNoTracking behavior may additionally work below,
services.AddDbContext<TestDbContext>(
a => a.UseInMemoryDatabase(databaseName: "TestDb").UseQueryTrackingBehavior(QueryTrackingBehavior.NoTracking),
ServiceLifetime.Singleton)
Also, how are you updating record? This seems to track in EFCore InMemory,
_dbContext.Entry(modifyItem).State = EntityState.Modified;
However, this doesn't seem to work as much.
_dbContext.Entry(existingItem).CurrentValues.SetValues(modifyItem);
I am currently using Mehdi El Gueddari's DbContextScope project, I think by the book, and it's awesome. But I came across a problem I'm unsure how to solve today. I have a query that I need to execute using a different database login/user because it requires additional permissions. I can create another connection string in my web.config, but I'm not sure how to specify that for this query, I want to use this new connection string. Here is my usage:
In my logic layer:
private static IDbContextScopeFactory _dbContextFactory = new DbContextScopeFactory();
public static Guid GetFacilityID(string altID)
{
...
using (_dbContextFactory.CreateReadOnly())
{
entity = entities.GetFacilityID(altID)
}
}
That calls into my data layer which would look something like this:
private AmbientDbContextLocator _dbcLocator = new AmbientDbContextLocator();
protected CRMEntities DBContext
{
get
{
var dbContext = _dbcLocator.Get<CRMEntities>();
if (dbContext == null)
throw new InvalidOperationException("No ambient DbContext....");
return dbContext;
}
}
public virtual Guid GetFaciltyID(string altID)
{
return DBContext.Set<Facility>().Where(f => f.altID = altID).Select(f => f.ID).FirstOrDefault();
}
Currently my connection string is set in the default way:
public partial class CRMEntities : DbContext
{
public CRMEntities()
: base("name=CRMEntities")
{}
}
Is it possible for this specific query to use a different connection string and how?
I ended up modifying the source code in a way that feels slightly hacky, but is getting the job done for now. I created a new IAmbientDbContextLocator with a Get<TDbContext> method override that accepts a connection string:
public TDbContext Get<TDbContext>(string nameOrConnectionString) where TDbContext : DbContext
{
var ambientDbContextScope = DbContextScope.GetAmbientScope();
return ambientDbContextScope == null ? null : ambientDbContextScope.DbContexts.Get<TDbContext>(nameOrConnectionString);
}
Then I updated the DbContextCollection to pass this parameter to the DbContext's existing constructor overload. Last, I updated the DbContextCollection maintain a Dictionary<KeyValuePair<Type, string>, DbContext> instead of a Dictionary<Type, DbContext> as its cached _initializedDbContexts where the added string is the nameOrConnectionString param. So in other words, I updated it to cache unique DbContext type/connection string pairs.
Then I can get at the DbContext with the connection I need like this:
var dbContext = new CustomAmbientDbContextLocator().Get<CRMEntities>("name=CRMEntitiesAdmin");
Of course you'd have to be careful your code doesn't end up going through two different contexts/connection strings when it should be going through the same one. In my case I have them separated into two different data access class implementations.
I am trying to use mvc-mini-profiler for db-first EF, but it is not working properly.
(note that I'm using objectcontext, not dbcontext)
Here is the list of stackoverflows I've tried:
Setup of mvc-mini-profiler for EF-db- first
How to get MVC-mini-profiler working on EF 4.1 Database First
versions:
Entity Framework: 4.3.1
MiniProfiler: 2.0.2
MiniProfiler.ef: 2.0.3
This is how I setup miniprofiler:
I've added the following stuff in Global.asax
protected void Application_BeginRequest(
{
MiniProfiler.Start();
}
protected void Application_EndRequest()
{
MiniProfiler.Stop();
}
protected void Application_Start()
{
...
MiniProfilerEF.Initialize_EF42();
}
Then configure an objectcontext,
var entityConnection = new EntityConnection(ConnectionString);
var profiledDbConnection = new EFProfiledDbConnection(entityConnection, MiniProfiler.Current);
var context = profiledDbConnection.CreateObjectContext<MyContext>();
var list = context.MyEntities.ToList();
If I execute this, the following exception occurs when running "context.MyEntities.ToList()"
[System.Data.EntityCommandCompliationException]
the message in the inner exception says:
EntityClient cannot be used to create a command definition from a store command tree.
Have I configured wrong? Any help?
thanks,
I use MiniProfiler and database first Entity Framework and it does work well. You may need to turn off the database initialization strategy inside of your database context as per this related answer: https://stackoverflow.com/a/9762989/325727
public class EmployeeContext : DbContext
{
static EmployeeContext() { Database.SetInitializer<EmployeeContext>(null); }
public IDbSet<Employee> Employees { get; set; }
}
The parameter null turns off database initialization by making sure that there is no initializer available.
I am using EF4, Microsoft.Entity.CTP, and the latest MOQ. I am trying to create a generic repository class and moq the DBContext using MOQ. Whenever I run my moq test I get "object reference not set to an instance of an object" on this.context.Set().Add(entity); and I don't understand why. The code runs ok without a moq.
public class GenericRepository<TEntity> : IGenericRepository<TEntity> where TEntity : class
{
private IContext context;
public GenericRepository(IContext context)
{
this.context = context;
}
public IList<TEntity> List
{
get { return context.Set<TEntity>().ToList(); }
}
public void Create(TEntity entity)
{
this.context.Set<TEntity>().Add(entity);
this.context.SaveChanges();
}
}
var mock = new Mock<IContext>();
GenericRepository<Product> producRepository = new GenericRepository<Product>(mock.Object);
mock.Setup(x => x.Product.Add(productType));
mock.Setup(x => x.SaveChanges());
productRepository.Create(product);
mock.VerifyAll();
You need to mock out the list implementation behind Set. I'm not at the compute ATM but iirc it's an IDbSet.
Change your code first definitions from DbSet to IDbSet and then you can mock them.
http://blogs.msdn.com/b/efdesign/archive/2010/06/21/productivity-improvements-for-the-entity-framework.aspx
I am considering changing my DbContext.tt file to generate IDbSet instead of DbSet, but only after I get the mocking to work.
I am not saying this makes the rest of the work easy, but it will get you past one problem.
What I need help with is what to do after changing my code first definitions to be based on the EF DbContext interfaces. For example, I create instances of my DbSet objects and add them.
Mock<IPosManContext> posManContext;
posManContext.Object.Set(typeof(note_template));
posManContext.Object.note_template.Add(
new note_template()
{
note_template_id = 1,
act_flag = "Y",
desc_text = "Monday Monday",
last_update_dtm = now,
last_update_user_id = "hsimpson",
});
But I get an error that the DbSet is null.
Microsoft needs to provide a good example of what to do.
They went half the way by providing public interfaces for mocking, but I still need more help.
Joe
At work we currently have a very large web application with a connection to a massive database. We have been using Entity Framework for a while now and to make things easier we divided the database into many Entity models. This works well for us but we ran into an issue. Each EF model needs its own connection string due to the metadata part of the connection string. Managing so many connection string is a pain.
Now I have a solution that I think will work. I am going to create a class that will have the metadata info saved as a property also concatenated to the standard connection string in the web.config. So when we use the connection string "Database.EntityConnectionString" it will give me the Entity Connection string but we only have to manage a single connection string in the web.config. We will still have to manage the class with the metadata but Models don't change very much and we don't create them often so maintenance should be fine. My question, is there a better way of dealing with this issue or how would you do it?
Thanks!
This is how I have implemented my solution to this problem:
namespace DBLibrary
{
public enum Models
{
Model1,
Model2
}
public static class Database
{
public static string EntitiesConnectionString(Models model)
{
SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder(ConfigurationManager.ConnectionStrings["Default"].ConnectionString);
builder["MultipleActiveResultSets"] = true;
builder["Connect Timeout"] = 30;
EntityConnectionStringBuilder entityBuilder = new EntityConnectionStringBuilder();
entityBuilder.Provider = "System.Data.SqlClient";
entityBuilder.ProviderConnectionString = builder.ConnectionString;
switch (model)
{
case Models.Model1:
entityBuilder.Metadata = "res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl";
return entityBuilder.ToString();
case Models.Model2:
entityBuilder.Metadata = "res://*/Model2.csdl|res://*/Model2.ssdl|res://*/Model2.msl";
return entityBuilder.ToString();
default:
throw new Exception("Invalid model, no connection string defined");
}
}
}
}
I still need to clean up the code and all but I think this give you a good idea on how this can be implemented. I would still be very interested if there are different and better ways of doing this.
Thanks!
Add Default Construction in your Class
public class ItemContext : DbContext
{
public DbSet<Item>Items get; set; }
public DbSet<ItemDetail> ItemDetails { get; set; }
public ItemContext ()
{
this.Database.Connection.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
}
}
I had the same problem. I have solved it by following way:
I have created two edmx file, but while creating second edmx file, i ignored the connection string to be save in config file. This way my config file will hold only one Connection string.
Then i modified following lines in my connection string:
<add name="MyDbContext" connectionString="metadata=res://*/;provider=System.Data.SqlClient;provider connection string="data source=abc;initial catalog=mydb;persist security info=True;user id=myuser;password=password;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
Just replace "res://model1.csdl" with "res://*/" and it works like a charm.
You can specify this connection name in constructor of your dbcontext class like:
public MyDbContext() : base("name=NameOfYourConnectionString") // Name of your connection string
{ }
Note: I am using Entity Framework 5.0.