MVC中集成Entity Framework的10个关键步骤
Table of Contents
- Introduction
- Understanding Entity Framework with MVC
- Pre-Requisites: Entity Framework Questions and Answers
- Creating the Customer Screen
- Interacting with the Database
- Adding Entity Framework to the Project
- Implementing a Three-Layer Architecture
- Creating the Data Access Layer
- Using Code First Approach
- Mapping the Customer Class with the Database Table
- Adding Connection STRING to the Web.config File
- Inserting Data into the Database
- Conclusion
Introduction
In this article, we will explore how to integrate Entity Framework with MVC (Model-View-Controller). We will discuss the importance of Entity Framework in MVC projects and how to use it effectively. Before diving into the main topic, we recommend watching our Entity Framework Questions and Answers video series to get a better understanding of EF.
Understanding Entity Framework with MVC
To fully comprehend Entity Framework's role in MVC, it is crucial to understand the three-layer architecture. MVC projects consist of the user interface, middle layer, and data access layer. While MVC has most of the sections of this architecture, the missing piece is often the data access layer. Entity Framework bridges this gap by acting as the data access layer, allowing seamless communication with the SQL Server database.
Pre-Requisites: Entity Framework Questions and Answers
Before proceeding further, we suggest watching our Entity Framework Questions and Answers video series. This series delves into the different approaches to using Entity Framework in a project, including the wizard approach, POCO approach, and code-first approach. Understanding these approaches is essential for becoming a skilled MVC professional.
Creating the Customer Screen
In MVC, the customer screen is a crucial component that requires proper validation and interaction with the database. An incomplete customer screen is insufficient without integrating it with the database. In order to interact with the database, we will be utilizing Entity Framework. To start, we need to Create a customer table with customer code and customer name fields.
Interacting with the Database
To Interact with the database, we need to reference Entity Framework in our project. We can do this using the NuGet Package Manager, which simplifies the process of adding references to projects. By adding Entity Framework via the NuGet Package Manager, we ensure that the appropriate assemblies are included in our project.
Adding Entity Framework to the Project
Before proceeding with integrating Entity Framework, we need to add a reference to it. By using the NuGet Package Manager, we can search for and install the Entity Framework package. Once added, we can confirm its inclusion by checking the references section.
Implementing a Three-Layer Architecture
Implementing a three-layer architecture in MVC projects has several advantages. It allows for better organization and maintenance of the project, as each layer can be managed separately. In our Current MVC project, we already have the user interface and middle layer, but We Are missing the data access layer. This is where Entity Framework comes into play, providing the necessary functionality for the data access layer.
Creating the Data Access Layer
To create the data access layer, we need to inherit from the DB Context class of the Entity Framework library. This class enables communication with the database and allows the retrieval of customer data. Additionally, we need to define the mapping between the customer class and the database table using the model builder object.
Using Code First Approach
For our MVC project, we will be using the code-first approach. This approach provides complete control over the data access methodology and eliminates the need for auto-generated code behind. By using the bare minimum DLLs of Entity Framework, we can seamlessly integrate the data access layer.
Mapping the Customer Class with the Database Table
To ensure Entity Framework understands the mapping between the customer class and the database table, we need to provide explicit mappings. By overriding the OnModelCreating method and using the model builder object, we can define the mapping between the customer class and the TBL customer table.
Adding Connection String to the Web.config File
In order for the data access layer to connect with the SQL Server database, we need to provide the connection string. The connection string specifies the server, database, and other pertinent details. We can obtain the connection string from the server explorer in Visual Studio and add it to the web.config file.
Inserting Data into the Database
Once all the necessary configurations are in place, we can proceed with inserting data into the database. To accomplish this, we need to create an object of the data access layer class, add the customer object to the collection, and save the changes to the database. By executing these steps, we can successfully insert records into the database.
Conclusion
In this article, we covered the process of integrating Entity Framework with MVC projects. We explored the importance of Entity Framework in the three-layer architecture and discussed the code-first approach. By following the steps outlined in this article, You can effectively utilize Entity Framework in your MVC projects, enabling seamless interaction with the database.
Highlights
- Integrating Entity Framework with MVC projects
- Understanding the three-layer architecture in MVC
- Exploring different approaches to using Entity Framework
- Adding Entity Framework to the project using NuGet
- Creating a data access layer with Entity Framework
- Mapping the customer class with the database table
- Adding the connection string to the web.config file
- Inserting data into the database using Entity Framework
- Achieving better organization and maintenance of MVC projects
- Becoming a proficient MVC professional
FAQ:
Q: What is Entity Framework?
A: Entity Framework is a Microsoft-recommended framework for accessing data in a variety of databases, including SQL Server and Oracle.
Q: What is the three-layer architecture in MVC?
A: The three-layer architecture in MVC consists of the user interface, middle layer, and data access layer. It allows for better organization and maintenance of projects.
Q: Which approach is recommended for Entity Framework in MVC projects?
A: The code-first approach is recommended for professional MVC projects, as it provides complete control over the data access methodology.
Q: How do I add Entity Framework to my project?
A: Entity Framework can be added to a project using the NuGet Package Manager. Simply search for "Entity Framework" and install the package.
Q: How do I insert data into the database using Entity Framework?
A: To insert data into the database using Entity Framework, you need to create an object of the data access layer class, add the desired object to the collection, and save the changes to the database using the SaveChanges method.