What is model builder in Entity Framework?
Provides a simple API surface for configuring a IMutableModel that defines the shape of your entities, the relationships between them, and how they map to the database. You can use ModelBuilder to construct a model for a context by overriding OnModelCreating(ModelBuilder) on your derived context.
What is DB set in Entity Framework?
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.
What is ModelBuilder in EF core?
The ModelBuilder is the class which is responsible for building the Model. The ModelBuilder builds the initial model from the entity classes that have DbSet Property in the context class, that we derive from the DbContext class. It then uses the conventions to create primary keys, Foreign keys, relationships etc.
How often is OnModelCreating called?
OnModelCreating will be called only once that’s default behaviour. According to OnModelCreating documentation. Typically, this method is called only once when the first instance of a derived context is created. The model for that context is then cached and is for all further instances of the context in the app domain.
What is DB set and entity set uses?
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. Adds the given entity to the context with the Added state.
What is DB context 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.
What is entity type configuration?
Allows configuration to be performed for an entity type in a model. An EntityTypeConfiguration can be obtained via the Entity method on DbModelBuilder or a custom type derived from EntityTypeConfiguration can be registered via the Configurations property on DbModelBuilder.
What is entity and entity set?
An entity in DBMS is used to represent any real-world object, while an entity set in DBMS is a set or collection of entities of similar types. In relational models, i.e., the tabular representation to represent data, each row in a table is a separate entity while the whole table is an entity set.
What is entity set and entity type?
Entity type is the category of a particular entity in the table of an RDBMS; in contrast, entity set refers to the collection of all entities of the same entity type in RDBMS. Thus, this is the main difference between Entity Type and Entity Set.
What is DB context in MVC?
DbContext is a class provided by Entity Framework to establish connection to database, query the db and close connection. Extending DbContext permits to define database model with DbSet (specific Set mapped to a table or more), create a database, query a database…
How do I configure Entity Framework?
In this tutorial, you:
- Create an MVC web app.
- Set up the site style.
- Install Entity Framework 6.
- Create the data model.
- Create the database context.
- Initialize DB with test data.
- Set up EF 6 to use LocalDB.
- Create controller and views.
What is ModelBuilder in Entity Framework?
Microsoft.EntityFrameworkCore v5.0.0 Provides a simple API surface for configuring a IMutableModel that defines the shape of your entities, the relationships between them, and how they map to the database. You can use ModelBuilder to construct a model for a context by overriding OnModelCreating (ModelBuilder) on your derived context.
What are entity properties in EF Core?
Each entity type in your model has a set of properties, which EF Core will read and write from the database. If you’re using a relational database, entity properties map to table columns. By convention, all public properties with a getter and a setter will be included in the model.
What is the purpose of the ModelBuilder?
The same ModelBuilder instance so that additional configuration calls can be chained. Performs configuration of a given entity type in the model. If an entity type with the provided name is not already part of the model, a new entity type that does not have a corresponding CLR type will be added to the model.
What is the use of action?
Entity (Type, Action ) Performs configuration of a given entity type in the model. If the entity type is not already part of the model, it will be added to the model. This overload allows configuration of the entity type to be done in line in the method call rather than being chained after a call to Entity ().