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Can DbContext be Singleton?
First, DbContext is a lightweight object; it is designed to be used once per business transaction. Making your DbContext a Singleton and reusing it throughout the application can cause other problems, like concurrency and memory leak issues. And the DbContext class is not thread safe.
Is the DbContext thread-safe?
DbContext is not thread-safe. Do not share contexts between threads. Make sure to await all async calls before continuing to use the context instance. An InvalidOperationException thrown by EF Core code can put the context into an unrecoverable state.
Is singleton thread-safe in C#?
Thread Safety Singleton In the code, the thread is locked on a shared object and checks whether an instance has been created or not. It takes care of the memory barrier issue and ensures that only one thread will create an instance.
How do you consume scoped service from Singleton?
To be able to use scoped services within a singleton, you must create a scope manually. A new scope can be created by injecting an IServiceScopeFactory into your singleton service (the IServiceScopeFactory is itself a singleton, which is why this works).
What is the difference between DbSet and DbContext?
DbContext corresponds to your database (or a collection of tables and views in your database) whereas a DbSet corresponds to a table or view in your database. So it makes perfect sense that you will get a combination of both!
How to use database context in Singleton service?
Original source: https://entityframeworkcore.com/knowledge-base/51939451/how-to-use-a-database-context-in-a-singleton-service- Since DbContext is scoped by default, you need to create scope to access it. It also allows you to handle its lifetime correctly – otherwise you’d keep instance of DbContext for a long time and this is not recommended.
How to create a thread safe singleton in C #?
You could eagerly create the a thread-safe Singleton instance, depending on your application needs, this is succinct code, though I would prefer @andasa’s lazy version. This is called Double checked locking mechanism, first, we will check whether the instance is created or not.
How to use adddbcontext in Singleton injected class?
As mentioned early.AddDbContext extension is adding it as scoped per request. So DI can not instantiate Scoped object to construct Singleton one. You must create and dispose instance of MyDbContext by yourself, it is even better because DbContext must be disposed after using as early as possible.
How to create a dbcontextfactory class in C #?
What would be ideal is if you created a DbContextFactory class to build you instances of your DbContext. Add a private readonly field for the factory and build a new context object for each database interaction. DBContext also has a cache that I would like to leverage for queries behind a WebAPI.