BrokenBatchDeleteExample.cs

using System.Linq;
using Microsoft.EntityFrameworkCore;
using Z.EntityFramework.Plus;

namespace BrokenBatchDeleteExample
{
    class Program
    {
		public static void Main()
		{
			// An index is required for the key only for SQL Compact.
			CreateBDWithIndex();

			GenerateData();

			// Delete: DELETE all rows from the database using a LINQ Query without loading entities in the context
			using (var context = new EntityContext())
			{
				// DELETE all customers that are inactive
				context.Customers.Where(x => !x.IsActive).Delete();
			}

			// Delete: DELETE all rows from the database using a LINQ Query without loading entities in the context
			using (var context = new EntityContext())
			{
				// DELETE customers by Name
				context.Customers.Where(x => x.Name =="Customer_B").Delete();
			}
		}

		public static void GenerateData()
		{

			using (var context = new EntityContext())
			{
				context.Customers.Add(new Customer() { Name ="Customer_A", IsActive = false  });
				context.Customers.Add(new Customer() { Name ="Customer_B", IsActive = true });
				context.Customers.Add(new Customer() { Name ="Customer_C", IsActive = false });

				context.SaveChanges();
			}
		}


		public static void CreateBDWithIndex()
		{
			using (var context = new EntityContext())
			{
				context.Database.EnsureCreated();

			}
		}

		public class EntityContext : DbContext
		{
			public string NameFilter { get; set; }

			protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
			{
				optionsBuilder.UseSqlite("Data Source=test.db");
			}

			protected override void OnModelCreating(ModelBuilder modelBuilder)
			{
				base.OnModelCreating(modelBuilder);

                // THE ACTUAL BUG CAN BE TOGGLED ON / OFF HERE
				// comment this line of code out, to make the application work
				modelBuilder.Entity<Customer>().HasQueryFilter(c => string.IsNullOrEmpty(NameFilter) || c.Name == NameFilter);
			}

			public DbSet<Customer> Customers { get; set; }
		}


		public class Customer
		{
			public int CustomerID { get; set; }
			public string Name { get; set; }
			public bool IsActive { get; set; }
		}
    }
}