Add a Global Query Filter to all Domain Entities in .NET

Assuming you have a base entity that all your core entities inherit from like so:

public abstract class BaseEntity
{
   public string Id { get; set; } = Guid.NewGuid().ToString();
   public bool IsDeleted { get; set; } = false;
   // …other properties
}

The old way of adding global query filters (there's an older way but I don't wanna go there)

builder.Entity<Address>().HasQueryFilter(m => !m.IsDeleted);
builder.Entity<Attribute>().HasQueryFilter(m => !m.IsDeleted);
builder.Entity<Brand>().HasQueryFilter(m => !m.IsDeleted);

Add the following to the OnModelCreating method of your ApplicationDbContext class

protected override void OnModelCreating(ModelBuilder builder)
{
   base.OnModelCreating(builder);
   // Apply global query filter for soft delete
   Expression<Func<BaseEntity, bool>> filterExpr = bm => !bm.IsDeleted;
   var baseEntityTypes = builder.Model.GetEntityTypes()
       .Where(entityType => entityType.ClrType.IsAssignableTo(typeof(BaseEntity)));
   foreach (var baseEntityType in baseEntityTypes)
   {
       var parameter = Expression.Parameter(baseEntityType.ClrType);
       var body = ReplacingExpressionVisitor.Replace(
           filterExpr.Parameters[0], parameter, filterExpr.Body);
       var lambdaExpression = Expression.Lambda(body, parameter);
       baseEntityType.SetQueryFilter(lambdaExpression);
   }
}

Now all your queries will automatically filter all soft-deleted entities.