What is Entity Framework

Introduction

Entity Framework (EF) is an object-relational mapping (ORM) framework for the Microsoft .NET Framework. It allows developers to work with a database using objects, eliminating the need to write SQL commands. EF provides a set of APIs for creating, querying, and updating data in a database, and it can work with a variety of databases, including SQL Server, MySQL, and SQLite. EF also includes a feature called Code First, which allows developers to create a database based on their model classes, and a feature called migrations, which makes it easy to update the database schema as the model classes change.

Versions of EF

There have been several versions of Entity Framework released over the years.

  1. Entity Framework 1.0 was released in 2008 as part of .NET Framework 3.5 Service Pack 1.
  2. Entity Framework 4.0 was released in 2010 as part of .NET Framework 4.0.
  3. Entities Framework 4.1 was released in 2011 as an update to EF 4.0.
  4. Entities Framework 4.3 was released in 2012, it was included in Visual Studio 2012 and .NET Framework 4.5.
  5. Entities Framework 5 was released in 2012 as part of .NET Framework 4.5.
  6. Entities Framework 6 was released in 2013 as part of .NET Framework 4.5.1.
  7. Entities Framework Core 2.0 was released in 2017
  8. Entities Framework Core 3.0 was released in 2019
  9. Entities Framework Core 5.0 was released in 2021.

Types of Entity Framework

  1. Entity Framework (EF) – the original version of Entity Framework, it is part of the .NET Framework, and it supports Windows-based applications.
  2. Entity Framework Core (EF Core) – a lightweight, open-source, and cross-platform version of Entity Framework. It can be used with various operating systems and platforms, including Windows, macOS, and Linux, and it can be used with various databases, including SQL Server, MySQL, and SQLite.

EF Core is an evolution of the original EF and it was first introduced in 2016. EF core is more efficient and it has been designed to support cloud-based, microservices, and container-based applications. EF Core is also an open-source, cross-platform, and lightweight version of EF, which can be used with .NET Core, .NET 5, and other .NET platforms, and it can work with various databases like SQL Server, MySQL, PostgreSQL, and SQLite

Databases that can be used

Entity Framework (EF) can connect to a variety of databases, including:

  1. SQL Server: EF supports all versions of SQL Server starting from 2005.
  2. SQL Server Compact: A lightweight version of SQL Server that can be used for desktop and mobile applications.
  3. SQLite: An open-source, lightweight, and cross-platform database that can be used with EF.
  4. MySQL: EF can connect to MySQL server through MySQL Connector/NET.
  5. PostgreSQL: EF can connect to the PostgreSQL server through Npgsql.
  6. Oracle: EF can connect to the Oracle server through Oracle Data Provider for .NET (ODP.NET)

Best Practice for Entity Framework

Here are some best practices for using Entity Framework (EF):

  1. Use the appropriate level of granularity when querying data. Use eager loading, lazy loading, and explicit loading to retrieve only the data that is needed, rather than retrieving all data and filtering it in memory.
  2. Use the appropriate type of query. Use LINQ to Entities to query data when working with a set of entities, and use Entity SQL or raw SQL when working with a single entity or a scalar value.
  3. Use the appropriate type of transaction. Use the DbContext.Database.BeginTransaction() method for explicit transactions and the TransactionScope class for implicit transactions.
  4. Use the appropriate type of change tracking. Use the DbContext.ChangeTracker.AutoDetectChangesEnabled property to enable or disable automatic change detection, and use the DbContext.ChangeTracker.Entries() method to manually track changes.
  5. Use the appropriate type of caching. Use the DbContext.ChangeTracker.QueryTrackingBehavior property to enable or disable query caching, and use the DbContext.Database.GetMemoryCache() method to access the query cache.
  6. Use the appropriate type of validation. Use the DbContext.ValidateOnSaveEnabled property to enable or disable automatic validation of entities before they are saved, and use the DbContext.ValidateEntity() method to manually validate entities.
  7. Use the appropriate type of concurrency control. Use the DbContext.ChangeTracker.DetectChanges() method and the DbContext.SaveChanges() method to control concurrency, and use the DbContext.ChangeTracker.Entries() method to access the original and current values of entities.
  8. Use the appropriate type of logging and debugging. Use the DbContext.Database.Log property to enable or disable logging, and use the DbContext.Database.GetDbConnection() method to access the underlying database connection.
  9. Use the appropriate type of performance tuning. Use the DbContext.ChangeTracker.QueryTrackingBehavior property to enable or disable query caching, and use the DbContext.Database.GetMemoryCache() method to access the query cache.
  10. Use the appropriate type of security. Use the DbContext.ChangeTracker.Entries() method to access the original and current values of entities, and use the DbContext.SaveChanges() method to control concurrency.

Tips and Tricks for using Entity Framework

Here are some tips and tricks for working with Entity Framework (EF):

  1. Use the AsNoTracking() method to improve performance when querying data that will not be updated. This will disable change tracking for the entities returned by the query, which can save memory and improve the performance of the query.
  2. Use the Include() method to eager load related data. This can improve the performance of your application by reducing the number of round trips to the database.
  3. Use the AsEnumerable() method to improve performance when working with large data sets. This will convert the query to an in-memory query, which can be faster than running the query in the database.
  4. Use the DbContext.Database.ExecuteSqlCommand() method to execute raw SQL commands. This can be useful when you need to perform a task that is not supported by EF, such as creating or dropping a table.
  5. Use the DbContext.Database.SqlQuery() method to execute a raw SQL query and return the results as an enumerable of entities. This can be useful when you need to retrieve data that is not mapped to an entity.
  6. Use the DbContext.Database.BeginTransaction() method to start a transaction. This can be useful when you need to perform a series of operations that must be atomic.
  7. Use the DbContext.ChangeTracker.Entries() method to access the entities that are being tracked by the context. This can be useful when you need to perform operations on the entities, such as validating or saving them.
  8. Use the DbContext.SaveChanges() method to save the changes made to the entities. This can be useful when you need to persist the changes made to the entities in the database.
  9. Use the DbContext.Dispose() method to release the resources used by the context. This can be useful when you need to free up memory or close the database connection.
  10. Use the DbContext.Database.Log property to enable or disable logging. This can be useful when you need to debug your application or when you need to troubleshoot a performance issue.

How to implement EF in a .NET application

There are several steps to implement Entity Framework (EF) in a .NET application:

  1. Install the Entity Framework package: You can install the EF package using the NuGet package manager or by adding the package to your project’s dependencies in the project.json file.
  2. Create a context class: This class is responsible for interacting with the database. It inherits from the DbContext class and defines the entities that are mapped to the database.
  3. Create entity classes: These classes represent the data in the application and correspond to the tables in the database. They should have properties that correspond to the columns in the table.
  4. Create a connection string: This string contains the information needed to connect to the database, such as the server name, the database name, and the username and password. It should be added to the app.config or web.config file.
  5. Create a data access layer: This layer contains the code that interacts with the database. It should have methods for performing CRUD operations on the entities.
  6. Use the context and data access layer in the application: The context and data access layer should be used in the application to perform operations on the entities and interact with the database.

Few Actions in Entity Framework

In Entity Framework (EF), there are several actions that can be performed on entities and their relationships, including:

  1. Add: This action is used to insert a new entity into the database.
  2. Attach: This action is used to attach an existing entity to the context, so that it can be tracked by EF.
  3. Update: This action is used to modify an existing entity in the database.
  4. Remove: This action is used to delete an existing entity from the database.
  5. SaveChanges: This action is used to persist all the changes made to the entities to the database.
  6. Reload: This action is used to refresh an entity’s state from the database.
  7. Find: This action is used to search for a specific entity in the database by its primary key.
  8. Get: This action is used to retrieve a specific entity from the context.
  9. ToList: This action is used to retrieve all the entities of a specific type from the context.
  10. Where: This action is used to filter a set of entities based on a specific condition.
  11. Select: This action is used to project a set of entities into a new form, usually an anonymous type or a DTO.
  12. Include: This action is used to load related entities along with the main entity from the database.
  13. ThenInclude: This action is used to load nested related entities along with the main entity from the database
  14. LazyLoadingEnabled: This action is used to enable or disable the lazy loading feature.

These actions can be used in various combinations and can be performed using LINQ queries, method calls, or a combination of both. It’s important to note that, some of these actions are only available in the latest versions of EF like, then include.

When to Use Entity Framework

  • When working with a relational database (e.g. SQL Server, MySQL, Oracle)
  • When you need to handle database-related tasks such as CRUD operations, data validation, and database schema management
  • When you need to support multiple database providers or need to switch between them easily
  • When you have a complex domain model and want to avoid writing a lot of SQL code
  • When you have a large team of developers and want to enforce a consistent data access pattern

When not to use Entity Framework

  • When you are working with a NoSQL database (e.g. MongoDB, Cassandra, RavenDB)
  • When you need to perform complex queries that involve multiple tables and require advanced SQL features (e.g. stored procedures, views, etc.)
  • When you need to handle large datasets and need to optimize performance
  • When you are working with legacy databases that have poor or inconsistent schema design
  • When you need to support real-time, low-latency scenarios where immediate data access is required

Conclusion

In this article, we delved into the topic of the Entity Framework and its intended function. I hope that you found this information useful. In future articles, we will delve deeper into the subject of the Entity Framework. We would greatly appreciate it if you could leave us your feedback in the comments section.

Leave a comment

Website Built with WordPress.com.

Up ↑