In the Table-Per-Hierarchy (TPH) inheritance strategy, how does Entity Framework differentiate between different types in a single table?
- By adding a discriminator column
- By creating a separate database for each type
- By creating separate columns for each type
- By using separate tables for each type
In the Table-Per-Hierarchy (TPH) inheritance strategy, Entity Framework differentiates between different types by adding a discriminator column to the table. This column stores a value that indicates the type of each entity. This approach allows all entities in the hierarchy to be stored in a single table, simplifying the database schema.
What is the primary challenge when using the Table-Per-Concrete class (TPC) inheritance strategy in Entity Framework?
- Complexity in querying across multiple tables
- Difficulty in maintaining referential integrity
- Duplication of columns in the database
- Limited support for polymorphism
The primary challenge of using the Table-Per-Concrete class (TPC) inheritance strategy in Entity Framework is the duplication of columns in the database. Each concrete type in the inheritance hierarchy gets its own table, leading to duplicated columns for shared properties across multiple types. This duplication can result in redundancy and increased storage space.
How can inheritance in Entity Framework be used to implement polymorphic behavior in a data model?
- By using Table-Per-Concrete-Class (TPinheritance strategy
- By using Table-Per-Entity (TPE) inheritance strategy
- By using Table-Per-Hierarchy (TPH) inheritance strategy
- By using Table-Per-Type (TPT) inheritance strategy
In Entity Framework, polymorphic behavior in a data model can be implemented using Table-Per-Hierarchy (TPH) inheritance strategy, where all types in the hierarchy are mapped to a single table. This approach simplifies the schema but may lead to NULL values for non-common attributes. It's suitable for scenarios with fewer subtypes and shared attributes.
What are the performance implications of using the Table-Per-Type (TPT) inheritance strategy in large datasets?
- Decreased memory usage
- Decreased query complexity
- Increased number of JOIN operations
- Increased storage space
Using Table-Per-Type (TPT) inheritance strategy in Entity Framework can lead to increased number of JOIN operations, as each entity type has its own table. This can impact performance, especially in large datasets, due to the increased complexity of queries and the need for multiple JOIN operations to retrieve related data.
How does Entity Framework handle inheritance when dealing with complex types and owned entities?
- Complex types and owned entities are stored in separate tables
- Complex types and owned entities are stored in the same table as the base entity
- Complex types are not supported in inheritance hierarchies
- Owned entities are treated as separate entities in the inheritance hierarchy
Entity Framework treats owned entities as separate entities in the inheritance hierarchy. They are mapped to their own tables and do not participate in inheritance. However, complex types are not supported in inheritance hierarchies and cannot be used as base or derived types. They are treated as part of the containing entity and mapped to columns within the same table.
The ________ strategy involves creating a single table for the base class and separate tables for each derived class.
- Table-Per-Concrete
- Table-Per-Entity
- Table-Per-Hierarchy
- Table-Per-Type
The Table-Per-Concrete (TPC) strategy involves creating a single table for the base class and separate tables for each derived class. Each table contains all properties of the corresponding class, resulting in a denormalized database schema.
When configuring TPH inheritance, the ________ attribute is used to designate a discriminator column in Entity Framework.
- Column
- Configuration
- Discriminator
- Inheritance
In Table Per Hierarchy (TPH) inheritance in Entity Framework, the Discriminator attribute is used to specify the column that serves as the discriminator. This column helps EF distinguish between different types of entities stored in the same table.
In advanced scenarios, the ________ method in Fluent API is used to configure complex inheritance mappings.
- Configure
- Map
- MapInherited
- MapInheritedProperties
In Entity Framework, the MapInheritedProperties method in Fluent API is employed in advanced scenarios to configure complex inheritance mappings. It allows developers to specify how properties are inherited and mapped between different entities.
To optimize queries in TPT inheritance, developers often need to address the issue of ________ due to multiple table joins.
- Impedance
- Joins
- Performance
- Polymorphism
In Table Per Type (TPT) inheritance, one common challenge is the issue of Impedance due to multiple table joins. This can impact query performance and efficiency, so developers must optimize their queries accordingly to mitigate this issue.
In a scenario where an application requires multiple types of user roles with shared and unique attributes, which inheritance strategy would be most efficient and why?
- TPC: This strategy maps each concrete class to its own table, providing a clear separation of concerns and potentially simplifying queries.
- TPH: This strategy minimizes the number of tables in the database, leading to simpler queries and potentially better performance.
- TPT: This strategy ensures that each entity type has its own table, which can improve query performance by reducing the size of individual tables.
- Table Per Hierarchy (TPH) strategy: Combines all entity types into a single table. Table Per Type (TPT) strategy: Creates a separate table for each type. Table Per Concrete class (TPC) strategy: Creates a table for each concrete class in the inheritance hierarchy. Table Splitting: Splits the properties of a single entity into multiple tables.
Table Per Hierarchy (TPH) strategy combines all entity types into a single table, which can lead to more efficient queries as it minimizes joins and reduces the complexity of the database schema. However, it may result in unused columns for certain entity types and can make the table less normalized. This strategy is suitable when there are few unique attributes across different types and when query performance is a priority.