Implementing Soft Delete in EF Core

What is Soft Delete?

Soft delete marks records as deleted without physically removing them from the database. This preserves data for audit trails, recovery, and historical analysis.

Implementation

public interface ISoftDeletable
{
    bool IsDeleted { get; set; }
    DateTime? DeletedAt { get; set; }
    string DeletedBy { get; set; }
}

public class Product : ISoftDeletable
{
    public int Id { get; set; }
    public string Name { get; set; }
    public bool IsDeleted { get; set; }
    public DateTime? DeletedAt { get; set; }
    public string DeletedBy { get; set; }
}

Global Query Filter

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Product>()
        .HasQueryFilter(p => !p.IsDeleted);
}

Override SaveChanges

public override int SaveChanges()
{
    foreach (var entry in ChangeTracker.Entries<ISoftDeletable>())
    {
        if (entry.State == EntityState.Deleted)
        {
            entry.State = EntityState.Modified;
            entry.Entity.IsDeleted = true;
            entry.Entity.DeletedAt = DateTime.UtcNow;
            entry.Entity.DeletedBy = _currentUser;
        }
    }
    
    return base.SaveChanges();
}

Usage

// Soft delete
var product = await context.Products.FindAsync(id);
context.Products.Remove(product);
await context.SaveChangesAsync(); // Sets IsDeleted = true

// Query active products
var products = await context.Products.ToListAsync(); // Only non-deleted

// Include deleted
var allProducts = await context.Products
    .IgnoreQueryFilters()
    .ToListAsync();

// Restore deleted
var product = await context.Products
    .IgnoreQueryFilters()
    .FirstAsync(p => p.Id == id);
product.IsDeleted = false;
product.DeletedAt = null;
await context.SaveChangesAsync();

Summary

Soft delete marks records as deleted instead of removing them. Implement using IsDeleted flag, global query filters, and override SaveChanges to intercept delete operations.