What is the role of Shadow Properties in Entity Framework?
- Caching database queries
- Handling complex data types
- Mapping to properties that are not defined in the entity class
- Tracking changes in entity state
In Entity Framework, Shadow Properties play a vital role in mapping properties that are not defined in the entity class. They allow mapping to database columns without corresponding properties in the entity class, useful for scenarios like auditing or data migration.
How does Entity Framework handle inheritance mapping for Entity Types?
- Table Per Class (TPC)
- Table Per Concrete Type (TPC)
- Table Per Hierarchy (TPH)
- Table Per Type (TPT)
Entity Framework uses Table Per Type (TPT) inheritance mapping to map each type to its own table in the database. This means that each subclass gets its own table, and the base class gets a table to hold shared properties. This approach allows for better normalization and reduces redundancy in the database schema.
To specify the length of a string property in an Entity Type, the ________ Data Annotation is used.
- DataLength
- MaxLength
- MinLength
- StringLength
The [StringLength] data annotation is used to specify the maximum length of a string property in an Entity Type in Entity Framework. This allows developers to enforce constraints on string lengths in the database schema.
In a scenario where you have an Entity Type with a complex type property, how do you ensure the complex type is properly configured in the database schema?
- Configure the complex type directly within the OnModelCreating method of the DbContext class.
- Define a separate EntityTypeConfiguration class for the complex type and configure it.
- Use Data Annotations to define the mapping of the complex type.
- Use the Fluent API to specify the configuration of the complex type.
In Entity Framework, when an entity has a complex type property, you can use the Fluent API to specify the configuration of the complex type. This involves defining the mapping and any additional configuration such as column names, data types, and constraints. This ensures that the complex type is properly configured in the database schema.
What are the implications of configuring an Entity Type as immutable in Entity Framework?
- Enhanced security
- Improved performance
- Reduced flexibility in data manipulation
- Simplified query optimization
Configuring an Entity Type as immutable in Entity Framework means that once an entity is created, its state cannot be changed. While this can lead to improved performance and enhanced security by preventing unintended modifications, it also reduces flexibility in data manipulation, as entities cannot be updated after creation. Additionally, query optimization may be simplified due to the immutable nature of the entities.
How can you implement Table per Type (TPT) inheritance in Entity Framework using Fluent API?
- Use the HasBaseType method
- Use the HasDiscriminator method
- Use the ToTable method
- Use the Map method
To implement Table Per Type (TPT) inheritance in Entity Framework using Fluent API, you can use the Map method. This method allows you to specify separate tables for each entity type in the inheritance hierarchy. By using the Map method, you can configure the mapping details for each entity type individually, including table names, column mappings, and any additional configuration options.
In Entity Framework, a property can be marked as required using the ________ Data Annotation or Fluent API.
- ForeignKey
- Index
- Key
- Required
In Entity Framework, the [Required] data annotation or .IsRequired() method in the Fluent API can be used to specify that a property in a model is required, meaning it cannot be null. This ensures data integrity and helps enforce business rules.
The ________ method in Fluent API is used to specify a foreign key relationship in Entity Framework.
- ForeignRelation
- HasForeignKey
- Relationship
- WithForeignKey
In Fluent API, the .HasForeignKey() method is used to specify a foreign key relationship between entities in Entity Framework. This method allows developers to define the foreign key property explicitly and configure the relationship between related entities.
To configure a property as a concurrency token in Entity Framework, the ________ Fluent API method is used.
- IsConcurrencyToken()
- ConcurrencyToken()
- IsRowVersion()
- HasConcurrencyToken()
The correct option is Option 3: IsRowVersion(). This method configures a property to be used as a concurrency token in Entity Framework. It marks the property as a row version, indicating that it should be included in concurrency checks when updating records in the database. This ensures that conflicting updates are detected and resolved appropriately, maintaining data integrity.
The ________ Fluent API method is utilized to configure a composite primary key in an Entity Type.
- HasKey
- CompositeKey
- PrimaryKey
- HasPrimaryKeys
The correct option is Option 2: CompositeKey. This method in Entity Framework's Fluent API is specifically designed to configure a composite primary key for an entity type. A composite primary key consists of more than one property that uniquely identifies a record in a table. By using CompositeKey, you can specify multiple properties to form the composite key, ensuring uniqueness across the combination of these properties.