What is DbSet used for?
A DbSet represents the collection of all entities in the context, or that can be queried from the database, of a given type. DbSet objects are created from a DbContext using the DbContext. Set method.
How do I get a DbSet?
You can get DbSet from DbContext by Type using the method DbContext. Set(Type entityType) . So if you have the model class name as string you should do some mapping to actual clr type.
What is meant by DbContext and DbSet?
Intuitively, a 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 can we remove an entity from DbSet?
You can use a stub to represent the entity to be deleted and thereby stop the entity being retrieved from the database:
- var context = new SampleContext();
- var author = new Author { AuthorId = 1 };
- context. Authors. Remove(author);
- context. SaveChanges();
What is DbSet class?
The DbSet class represents an entity set that can be used for create, read, update, and delete operations. The context class (derived from DbContext ) must include the DbSet type properties for the entities which map to database tables and views.
What is a DbContext?
A DbContext instance represents a combination of the Unit Of Work and Repository patterns such that it can be used to query from a database and group together changes that will then be written back to the store as a unit. DbContext is conceptually similar to ObjectContext.
What is FirstOrDefaultAsync?
FirstOrDefaultAsync(IQueryable) Asynchronously returns the first element of a sequence, or a default value if the sequence contains no elements.
What is DbContext?
How do I delete EF records?
Delete a Record In Connected Scenario, you can use the Remove or RemoveRange method to mark the record as Deleted . In Disconnected Scenario, you can attach it to the context and set its state as Deleted . Calling SaveChanges will send the delete query to the database.
What is DbContext and ObjectContext?
Definition. DBContext is a wrapper of ObjectContext that exposes the most commonly used features of ObjectContext. In contrast, Object Context is a class of the core Entity framework API that allows performing queries and tracking the updates made to a database using strongly typed entity classes.
