In Entity Framework, ________ loading can be achieved by using the Include method with DbSet queries.
- Deferred
- Eager
- Immediate
- Lazy
In Entity Framework, eager loading can be achieved by using the Include method with DbSet queries. Eager loading allows you to retrieve related entities along with the main entities in a single query, reducing the number of database round trips and improving performance.
The ________ method of DbContext can be overridden to configure domain classes using Fluent API.
- Configure
- Customize
- Mapping
- OnModelCreating
In Entity Framework, the OnModelCreating method of DbContext can be overridden to configure domain classes using Fluent API. This method is called when the model for a derived context has been initialized, allowing you to specify how the model should be configured.
To query the database using LINQ in Entity Framework, you typically use the ________ property of DbContext.
- Context
- Data
- DbSet
- Query
In Entity Framework, to query the database using LINQ, you typically use the DbContext class's Set property, which provides access to the entities of a specific type. The Set property allows you to perform LINQ queries against the database.
Describe the behavior of DbContext when DbSet.Attach() is used on an entity.
- Attaches the entity and marks it as modified in the DbContext.
- Attaches the entity to the DbContext in an unchanged state.
- Detaches the entity from the DbContext, allowing it to be re-attached with changes.
- Throws an exception if the entity is already being tracked by the DbContext.
When DbSet.Attach() is used on an entity in Entity Framework's DbContext, it attaches the entity to the context in an unchanged state. This means that the entity is considered to exist in the database in its current state, and any changes made to it will not be tracked by the context unless explicitly marked as modified. This is useful when working with entities that are not being modified but need to be included in queries or related operations.
Which method in DbContext is used to save changes to the database?
- CommitChanges()
- SaveChanges()
- SubmitChanges()
- UpdateDatabase()
In Entity Framework, the SaveChanges() method in the DbContext is used to persist changes made to entities to the underlying database. When you modify, add, or delete entities in a DbContext, you need to call SaveChanges() to ensure that these changes are reflected in the database. This method executes SQL statements necessary to synchronize the state of the entities with the database, committing the changes within a transaction if all changes succeed.
When implementing a complex transaction involving multiple DbSet operations, how does DbContext manage these operations to ensure data consistency?
- DbContext applies compensating transactions for rollback
- DbContext employs distributed transactions for consistency
- DbContext ensures atomicity of transactions
- DbContext uses savepoints to isolate operations
DbContext ensures atomicity of transactions when dealing with complex transactions involving multiple DbSet operations. This ensures that either all operations within the transaction are successfully completed, or none of them are, maintaining data consistency.
In a scenario where multiple users are modifying the same data, how does DbContext ensure data integrity?
- Automatic conflict resolution
- Explicit locking
- Optimistic concurrency control
- Pessimistic concurrency control
DbContext utilizes optimistic concurrency control to ensure data integrity in scenarios where multiple users are modifying the same data. This approach relies on versioning and optimistic locking to detect and handle conflicts, minimizing the risk of data inconsistency.
In Model-First approach, which tool is typically used to create the conceptual model?
- Code-First Migration
- Database Designer
- Entity Data Model Designer (EDMX)
- LINQ to Entities
In the Model-First approach, the Entity Data Model Designer (EDMX) is typically used to create the conceptual model. This tool allows developers to visually design the model and generate the corresponding code.
What is a key advantage of the Database-First approach in Entity Framework?
- Better Performance
- Full Control over Database
- Less Dependency on ORM Framework
- Rapid Development
A key advantage of the Database-First approach in Entity Framework is rapid development. This approach allows developers to quickly generate entity classes and the context from an existing database, speeding up development time.
In the Code-First approach, how are database schema changes managed?
- Code Generation
- Database Designer
- Entity Data Model
- Migrations
In the Code-First approach, database schema changes are managed using migrations. Migrations allow developers to incrementally update the database schema as the code evolves, ensuring smooth transitions and version control.
Which approach requires the database to be designed first, followed by the generation of entity classes?
- Code First
- Database First
- Entity First
- Model First
Database First approach requires the database schema to be designed first using tools like SQL Server Management Studio or other database design tools. Then, Entity Framework generates entity classes based on the existing database schema. This approach is suitable for scenarios where the database already exists or when working with legacy databases.
Which Entity Framework approach involves designing the database schema in a visual designer before generating the code?
- Code First
- Database First
- Entity First
- Model First
Model First approach involves designing the database schema visually using Entity Framework Designer in Visual Studio before generating the code. Developers can create entity types, relationships, and mappings using the designer, and then the corresponding code classes are generated from the model. This approach is useful when the database schema is finalized early in the development process.