Using Entity Framework Core with Existing Database

We can use an existing database with Entity Framework Core (in this example is a MSSQL Database and EF Core 7). Say we need to create a new app that is accessing data from an established database. First we need to generate models and context class from our database. Then our codes can interact with these generated classes.

First of all, install Microsoft.EntityFrameworkCore, Microsoft.EntityFrameworkCore.Tools and Microsoft.EntityFrameworkCore.SqlServer packages to our project.

Then run Scaffold-DbContext command to generate models and context class. I would like to structure my projects like this:

To have this, I need to use some flags when running the command:

Scaffold-DbContext "Server=[SERVER_NAME];Database=[DATABASE_NAME];TrustServerCertificate=True;Trusted_Connection=True" Microsoft.EntityFrameworkCore.SqlServer -OutputDir "[MY_APP_DIRECTORY]\StudentApp\Model\Entity" -Namespace Model.Entity -Context StudentAppContext -ContextDir . -ContextNamespace Repository -Tables Student,School -Force

In my case, I use an Active Directory account that can access my database, so I use 'Server=[SERVER_NAME];Database=[DATABASE_NAME];TrustServerCertificate=True;Trusted_Connection=True'.
The flags used here:
- OutputDir - folder location where the generated model classes will be put
- Namespace - the namespace of the generated model classes
- Context - the name of the context file to be generated
- ContextDir - folder location where the context file will be put. I use '.' for current directory (I run the command from Repository project).
- ContextNamespace - namespace of the context file
- Tables - specify all table names in the database that we want to map
- Force - useful when we want to add new model(s) to be generated or simply to generate the whole thing again if we made mistake

Later when we want to add another model(s) from different table(s), we run the same command again with the new table name(s) added. For example if we want to add Teacher and Subject models:

Scaffold-DbContext "Server=[SERVER_NAME];Database=[DATABASE_NAME];TrustServerCertificate=True;Trusted_Connection=True" Microsoft.EntityFrameworkCore.SqlServer -OutputDir "[MY_WORK_DIRECTORY]\StudentApp\Model\Entity" -Namespace Model.Entity -Context StudentAppContext -ContextDir . -ContextNamespace Repository -Tables Student,School,Teacher,Subject -Force