Why Does My Entity Framework Code Throw 'The entity type is not part of the model for the current context'?

Understanding Entity Mapping Errors in Entity Framework

In your code-first Entity Framework approach, you encountered the error "The entity type is not part of the model for the current context." This indicates that the entity you're trying to access or modify is not recognized by the DbContext.

The Role of Entity Mapping

In code-first, EF infers the entities and mappings from your domain classes. However, sometimes explicit mapping is necessary, especially when the entity names or table names differ. The OnModelCreating method in the custom DbContext class allows you to define this mapping.

Custom Mapping for Entity

To solve your issue, add the following code to the OnModelCreating method in your DbContext:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<Estate>().ToTable("Estate");
}

This instructs EF to map the Estate entity to the "Estate" table. Ensure that this table already exists in your database or that migrations are enabled.

Additional Tips

• Separate mapping configuration: Instead of defining the mapping in the DbContext, you can create separate EntityTypeConfiguration classes to manage mappings for specific entities.
• Database Initialization: If your tables are not created automatically, you may need to enable database initialization or manually create the tables.
• Automatic Migration: Enable automatic migrations to automatically update the database schema based on model changes.

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