Updating the Model - (EF Database First Development)

Entity Framework (EF) is a popular object-relational mapper that enables developers to work with databases using object-oriented code. In this tutorial, we'll discuss updating the model in Entity Framework using the Database First development approach.

Syntax

To update the model in Entity Framework using the Database First approach, follow these steps:

1. Make changes to the database schema
2. Update the EDMX file by right-clicking on the diagram and selecting "Update Model from Database"
3. Select the tables and/or views that you want to update, then click "Finish"
4. Build the project to regenerate the code based on the updated schema

Example

Suppose you have an existing database with a table named Customers that contains the following columns:

• id (int)
• name (varchar(100))
• address (varchar(200))

You decide to add a new column named phone_number (varchar(20)) to the Customers table. To update the EDMX file to reflect this change, you would follow these steps:

1. Add the new phone_number column to the Customers table in the database.
2. In Visual Studio, right-click on the EDMX diagram and select "Update Model from Database".
3. Select the Customers table and click "Finish".
4. Build the project to regenerate the code based on the updated schema.

After following these steps, you can access the phone_number column in the Customers table in your C# code using Entity Framework.

Explanation

When using Entity Framework with a database-first development approach, the EDMX file is used as the model for the database schema. If the database schema changes, the EDMX file must be updated to reflect those changes. This can be done by using the "Update Model from Database" feature in Visual Studio, which will update the EDMX file to reflect the changes in the database schema.

Use

Updating the model in Entity Framework using the Database First development approach is useful when you need to make changes to the database schema and have those changes reflected in your C# code.

Important Points

Here are some important points to keep in mind when updating the model in Entity Framework using the Database First approach:

• Always back up the EDMX file before making changes.
• Make sure to regenerate the code by building the project after updating the EDMX file.
• Be mindful of any manual changes you have made to the generated code, as these changes may be overwritten when regenerating the code.

Summary

In this tutorial, we discussed updating the model in Entity Framework using the Database First development approach. We covered syntax, example, explanation, use, and important points of updating the model in Entity Framework. By following these steps, you can ensure that your C# code is in sync with the database schema and take advantage of the benefits of using Entity Framework for working with databases.