Naming Conventions in Entity Framework

4 min
Beginner

In this tutorial, we will see the naming conventions, default rules that the framework uses to map C# classes to database tables.

EF Core follows a set of conventions to generate names for tables, columns, primary keys, and foreign keys, which allow EF to infer the structure of the database.

If we follow these conventions, EF will generate the database schema without the need for additional configuration (although we can later customize this configuration).

Let’s look at the main ones,

Table Naming Convention

By default, EF Core uses the class name for the table name in the database.

That is, if you have a C# class called Product, EF Core will automatically generate a table called Products (in plural) in the database.

public class Product  
{  
    public int Id { get; set; }  
    public string Name { get; set; }  
}

This will be mapped in the database to:

CREATE TABLE Products (  
    Id INT PRIMARY KEY,  
    Name NVARCHAR(MAX)  
);

Column Naming Convention

By default, EF Core uses the property name of the class as the column name in the database.

For example, if the class Student has a property called Name, EF Core will generate a column called Name in the corresponding table.

public class Student
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
}

In this case, EF will create the columns Id, Name, and Age in the Students table.

The types are inferred from the data type in C# (string → NVARCHAR, int → INT, etc.).

Primary Key Naming Convention

EF Core has a convention for recognizing the primary key of each entity. If an entity has a property called Id or the class name followed by Id.

For example, if we have StudentId for the class Student, EF Core will use it as the primary key of the table.

public class Student
{
    public int StudentId { get; set; }  // Convention for the primary key
    public string Name { get; set; }
    public int Age { get; set; }
}

In this case, EF Core will automatically recognize the property StudentId as the primary key of the Students table.

EF follows these rules to identify primary keys:

A property named Id or {ClassName}Id is considered a primary key.
If it is of type int, Guid, or similar, it will be configured as auto-incrementing.

Foreign Key and Relationship Naming Convention

When there are relationships between entities, EF Core will look for a property whose name is the name of the related entity followed by Id.

For example, if you have a relationship between Student and Course, EF Core will look for a property called CourseId to represent it as the foreign key.

public class Course
{
    public int CourseId { get; set; }
    public string Name { get; set; }
    public ICollection<Student> Students { get; set; }
}

public class Student
{
    public int StudentId { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }

    public int CourseId { get; set; }  // Convention for the foreign key
    public Course Course { get; set; }
}

In this case, EF Core will recognize the property CourseId in the Student class as the foreign key that relates to the Courses table.

How to Customize or Disable Conventions

We can modify the default behavior using Data Annotations or Fluent API (we will see this in upcoming tutorials).

Additionally, if we need to modify the default behavior globally, we can add or modify naming conventions.

Add Conventions

protected override void ConfigureConventions(ModelConfigurationBuilder builder)  
{  
    builder.Properties<string>()  
        .HaveMaxLength(100); // All string properties will have a maximum length of 100 characters  
}

Remove Conventions

protected override void OnModelCreating(ModelBuilder modelBuilder)  
{  
    // Remove the pluralization convention  
    modelBuilder.Model.GetEntityTypes()  
        .ToList()  
        .ForEach(e => e.SetTableName(e.DisplayName()));  
}