ApplyManyToOne

Configures a many-to-one relationship from a dependent entity to a principal entity. The method starts from the dependent entity, uses the dependent reference navigation, configures the dependent foreign key, applies delete behavior, and optionally sets a principal key.

Use this method when the model code is written from the dependent side of the relationship. This is useful for entities such as sessions, orders, or audit records that each point back to one owning entity.

Usage

using Microsoft.EntityFrameworkCore;
using AlmightyShogun.EntityFrameworkCore.Utils;

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.ApplyManyToOne<User, UserSession>(
        session => session.User,
        session => session.UserId,
        isRequired: true
    );
}

Parameters

navigation: Expression<Func<TDependent, TEntity?>>
Reference navigation on the dependent entity pointing to the principal entity.

foreignKey: Expression<Func<TDependent, object?>>
Foreign key property on the dependent entity.

principalKey: Expression<Func<TEntity, object?>>?
Optional principal key property. When omitted, EF Core uses the principal primary key.
Default: null

isRequired: bool
Whether the dependent relationship is required.
Default: false

deleteBehavior: DeleteBehavior
Delete behavior applied to the relationship.
Default: DeleteBehavior.ClientSetNull

Type signature

public void ApplyManyToOne<TEntity, TDependent>(
    Expression<Func<TDependent, TEntity?>> navigation,
    Expression<Func<TDependent, object?>> foreignKey,
    Expression<Func<TEntity, object?>>? principalKey = null,
    bool isRequired = false,
    DeleteBehavior deleteBehavior = DeleteBehavior.ClientSetNull
) where TEntity : class where TDependent : class;