ApplyOneToMany

Configures a one-to-many relationship where TEntity is the principal entity and TDependent is the dependent entity. The method starts from the principal collection navigation, configures the dependent foreign key, applies delete behavior, and optionally sets a principal key.

Use this method when a principal entity owns a collection of dependents and the dependent entity stores the foreign key. The default relationship is optional unless isRequired is set to true.

Usage

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

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.ApplyOneToMany<User, UserSession>(
        user => user.Sessions,
        session => session.UserId,
        deleteBehavior: DeleteBehavior.Cascade
    );
}

Parameters

navigation: Expression<Func<TEntity, IEnumerable<TDependent>?>>
Collection navigation on the principal entity containing dependent entities.

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 ApplyOneToMany<TEntity, TDependent>(
    Expression<Func<TEntity, IEnumerable<TDependent>?>> 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;