Posted onMar 16, 2024 • Edited onMar 19, 2024

Implementing Soft Delete With EF Core.

#efcore #softdelete #softdeletewithefcore #softdeleteindotnetcore

What is soft delete?

Prevents permanent deletion of records.
Flag set on record, indicating "delete".
Allows for easy restoration and maintains data integrity.

How to implement:

Create Marker Interface.

Define a marker interface ISoftDelete to mark entities that support soft delete.

public interface ISoftDelete{    bool IsDeleted { get; set; }    DateTime? DeleteOnUtc { get; set; }}

Implement Soft Delete Interceptor.

Create a class SoftDeleteInterceptor to handle soft deletes in EF Core.

public sealed class SoftDeleteInterceptor: SaveChangesInterceptor{    public override ValueTask<InterceptionResult<int>> SavingChangesAsync(        DbContextEventData eventData,        InterceptionResult<int> result,        CancellationToken cancellationToken = default)    {        if (eventData.Context is null)        {            return base.SavingChangesAsync(eventData, result, cancellationToken);        }        IEnumerable<EntityEntry<ISoftDeletable>> entries =            eventData.Context.ChangeTracker.Entries<ISoftDeletable>()                .Where(e => e.State == EntityState.Deleted);        foreach (EntityEntry<ISoftDeletable> softDeletable in entries)        {            softDeletable.State = EntityState.Modified;            softDeletable.Entity.IsDeleted = true;            softDeletable.Entity.DeletedOnUtc = DateTime.UtcNow;        }        return base.SavingChangesAsync(eventData, result, cancellationToken);    }}

Configure Application Context.

Configure EF Core to use the soft delete interceptor and global query filters.

public class ApplicationDbContext: DbContext{    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)        : base(options)    {    }    public DbSet<User> Users { get; set; }    protected override void OnModelCreating(ModelBuilder modelBuilder)    {        base.OnModelCreating(modelBuilder);        // HasQueryFilter is used to filter soft-deleted data automatically.        modelBuilder.Entity<User>().HasQueryFilter(r => !r.IsDeleted);        modelBuilder.Entity<User>()        .HasIndex(r=> r.IsDeleted)        .HasFilter("IsDeleted=0");        // This HasFilter method accepts the SQL filter for records that will be             included in the index.        // You can also create a filtered index using SQL:         /*           Create index IX_Users_IsDeleted on User(IsDeleted) where IsDelete =0;         */    }}

Register SoftDeleteIntercepter with dependency injection.

services.AddSingleton<SoftDeleteInterceptor>();services.AddDbContext<ApplicationDbContext>(    sp, options)=>options        .UseSqlServer(connectionString)        .AddInterceptor(               sp.GetRequiredService<SoftDeleteInterceptor>()));

Example Entity.

Create an example entity Review implementing the soft delete marker interface.

public class User: ISoftDeletable{    public int Id { get; set; }    public string UserName { get; set; }    public bool IsDeleted { get; set; }    public DateTime? DeletedOnUtc { get; set; }}