deleted child entity generate wrong query? - entity-framework

Question

the following code
using System;
using System.Linq;
using System.Data.Entity;
using System.Collections.Generic;
using System.Data.Entity.ModelConfiguration;
using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;
using System.Data.SqlClient;
using System.Reflection;
namespace testef {
public class Order {
public Int32 Id { get; set; }
public String O { get; set; }
public virtual ICollection<OrderDetail> Details { get; set; }
}
public class OrderDetail {
public virtual Order Order { get; set; }
public Int32 Id { get; set; }
public String D { get; set; }
public Boolean IsActive { get; set; }
}
public class OrderDetailConfiguration : EntityTypeConfiguration<OrderDetail> {
public OrderDetailConfiguration()
: base() {
HasRequired(d => d.Order).WithMany(o => o.Details);
}
}
public class TestEFContext : DbContext {
public DbSet<Order> Orders { get; set; }
public DbSet<OrderDetail> Details { get; set; }
public TestEFContext(String cs)
: base(cs) {
Database.SetInitializer<TestEFContext>(new DropCreateDatabaseAlways<TestEFContext>());
//Database.SetInitializer<TestEFContext>(null);
//Database.SetInitializer<TestEFContext>(new CreateDatabaseIfNotExists<TestEFContext>());
//Database.SetInitializer<TestEFContext>(new CustomDataBaseInitializer());
}
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
base.OnModelCreating(modelBuilder);
modelBuilder.Configurations.Add(new OrderDetailConfiguration());
}
}
public class CustomDataBaseInitializer : CreateDatabaseIfNotExists<TestEFContext> {
public CustomDataBaseInitializer() : base() {
}
}
class Program {
static void Main(string[] args) {
String cs = #"Data Source=ALIASTVALK;Initial Catalog=TestEF;Integrated Security=True; MultipleActiveResultSets=True";
using (TestEFContext ctx = new TestEFContext(cs)) {
Order o = new Order {
O = "O1",
Details = new List<OrderDetail>{
new OrderDetail { D = "D11", IsActive = true},
new OrderDetail { D = "D12", IsActive = false}
}
};
ctx.Orders.Add(o);
ctx.SaveChanges();
}
using (TestEFContext ctx = new TestEFContext(cs)) {
//OrderDetail d = new OrderDetail { Id = 1};
//ctx.Details.Attach(d);
OrderDetail d = ctx.Details.Where(x => x.Id == 1).First();
ctx.Details.Remove(d);
ctx.SaveChanges();
// ==> exec sp_executesql N'DELETE [dbo].[OrderDetails] WHERE (([Id] = #0) AND ([Order_Id] = #1))',N'#0 int,#1 int',#0=1,#1=1
}
}
}
}
generate following sql:
exec sp_executesql N'DELETE [dbo].[OrderDetails] WHERE (([Id] = #0) AND ([Order_Id] = #1))',N'#0 int,#1 int',#0=1,#1=1
I can't figure out why AND ([Order_Id] = #1. For me as the PK is Id a WHERE on Id must be enough!
Where am I wrong ?

Answer 1

It's a design decision the team made. I wouldn't consider either your stance or the EF teams tactic wrong...just choices. Both have benefits. I wouldn't get hung up on it, partially because deleting is uncommon in most applications, partially because there's an easy work around if performance is an issue.
If you want to execute just one query, do something like this:
ctx.Database.ExecuteSqlCommand("delete from [dbo].[OrderDetails] where Id = #p0", 1);