In advanced inheritance scenarios, the ________ method is used to configure specific mappings between an entity and a database table.
- ConfigureMap
- Map
- MapInheritance
- MapTo
In Entity Framework Core, the Map method is used in advanced inheritance scenarios to configure specific mappings between an entity and a database table.
To implement a TPC inheritance strategy, you need to override the ________ method and configure the mappings.
- OnConfiguring
- OnModelCreating
- OnModelCreating
- OnModelCreating
To implement a Table-Per-Concrete (TPC) inheritance strategy in Entity Framework, you need to override the OnModelCreating method in your DbContext class and configure the mappings for each concrete type separately.
In Table-per-Type (TPT) inheritance, each type in the hierarchy is mapped to a different ________.
- class
- context
- database table
- entity set
In Table-per-Type (TPT) inheritance, each type in the hierarchy is mapped to a different database table. This means that each concrete type in the inheritance hierarchy gets its own table in the database, which can lead to a normalized database schema.
What are the performance considerations when choosing between TPH, TPT, and TPC inheritance strategies in Entity Framework?
- All three strategies have similar performance characteristics
- TPC often leads to redundant data in multiple tables, increasing storage requirements and affecting performance
- TPH can result in wide tables with many nullable columns, impacting storage and query performance
- TPT requires additional joins for querying, potentially impacting performance
When choosing between TPH, TPT, and TPC inheritance strategies in Entity Framework, there are several performance considerations to keep in mind. TPH can result in wide tables with many nullable columns, which can impact storage and query performance, especially when dealing with large datasets. TPT requires additional joins for querying, potentially affecting performance, but it can provide better normalization and query performance compared to TPH in certain scenarios. TPC often leads to redundant data in multiple tables, increasing storage requirements and potentially affecting performance negatively. It's essential to analyze the specific requirements and trade-offs of each strategy to determine the most suitable one for a given scenario.
In an advanced scenario, how can you customize the mapping of inheritance hierarchies beyond the default strategies provided by Entity Framework?
- Customizing the SQL queries generated by Entity Framework
- Extending the base DbContext class to override default behavior
- Modifying the EDMX file directly
- Using fluent API to configure entity mappings
In advanced scenarios, you can customize the mapping of inheritance hierarchies beyond the default strategies provided by Entity Framework using the fluent API. This allows for fine-grained control over entity mappings, including specifying table names, column names, and relationships. Modifying the EDMX file directly is not recommended as it can be complex and error-prone. Customizing SQL queries or extending the base DbContext class may not provide the same level of flexibility as using the fluent API.
What is the primary use of stored procedures within Entity Framework?
- Enforcing business logic
- Enhancing performance and security
- Providing a way to write complex queries
- Simplifying database design
The primary use of stored procedures within Entity Framework is to enhance performance and security by reducing the amount of data sent between the database and the application, and by encapsulating business logic on the database server.
Can functions be executed directly in Entity Framework, and if so, how?
- No, Entity Framework does not support functions
- Yes, by creating a new instance of the function
- Yes, by using the DbContext's ExecuteFunction method
- Yes, by writing raw SQL queries
Functions can be executed directly in Entity Framework by using the DbContext's ExecuteFunction method, which allows invoking database functions mapped in the model.
How do you call a stored procedure in Entity Framework?
- By adding the stored procedure to the model
- By creating a SqlCommand object
- By executing a LINQ query
- By using the DbContext's Database property
In Entity Framework, stored procedures can be called by using the DbContext's Database property, which provides methods like ExecuteSqlCommand for executing SQL queries or stored procedures directly.
When dealing with a legacy database that has a non-standard table structure, how can you implement inheritance in Entity Framework to accommodate this?
- Use Joined Tables (JT) strategy, mapping each class in the hierarchy to its own database table with a one-to-one relationship between the base class table and derived class tables.
- Use Table per Concrete Type (TPstrategy, mapping each class to its own database table, including inherited properties.
- Use Table per Hierarchy (TPH) strategy to map all properties from all classes to a single database table.
- Use Table per Type (TPT) strategy, mapping each class in the hierarchy to its own database table.
Using the Table per Hierarchy (TPH) strategy would be the most appropriate approach. TPH allows mapping all properties from all classes to a single database table, making it suitable for accommodating non-standard table structures in legacy databases. This simplifies the mapping process and aligns well with the existing database schema, reducing the need for extensive schema modifications. However, it's essential to consider potential performance implications, such as NULL values and table size, when implementing this strategy.
Consider a situation where you have to map a complex class hierarchy with minimal database tables. Which inheritance strategy would you choose and what are its implications?
- Joined Tables (JT): Each class in the hierarchy maps to its own database table, with a one-to-one relationship between the base class table and derived class tables.
- Table per Concrete Type (TPC): Each class maps to its own database table, including inherited properties.
- Table per Hierarchy (TPH): All properties from all classes are mapped to a single database table.
- Table per Type (TPT): Each class in the hierarchy maps to its own database table.
Table per Hierarchy (TPH) strategy would be chosen. TPH reduces the number of database tables required by mapping all properties from all classes to a single database table. This strategy simplifies the database schema, making it easier to manage and understand. However, it may result in NULL values for properties specific to certain derived types, impacting database performance and storage efficiency.
To optimize performance in a TPH scenario, the ________ column should be indexed.
- BaseType
- Discriminator
- DiscriminatorColumn
- RootType
Indexing the Discriminator column in a Table-Per-Hierarchy (TPH) scenario can significantly improve query performance by quickly identifying the entity type.
What are the limitations of using stored procedures with Entity Framework?
- Difficulty in handling complex result sets
- Inability to use stored procedures for data manipulation operations
- Limited support for advanced database features
- Restrictions on executing stored procedures with dynamic SQL statements
Entity Framework has limitations when using stored procedures, such as limited support for advanced database features and restrictions on executing stored procedures with dynamic SQL statements.