在使用带有实体框架的Table-per-Type时，如何仅获取基表行？

Question

I have the following tables mapped in Entity Framework 4.2 as table-per-type.

Gear (ID, Name, Description) // base table
Weapon (ID, Damage, Bonus) // FK to Gear table.
Armor (ID, Kinetic, Energy) // FK to Gear table.

I can get the weapons and gear separately as such:

var weapons = db.Gear.OfType<Weapon>(); // Gets just weapons.
var armor = db.Gear.OfType<Armor>(); // Gets just armor.

but I can't figure out how to get just the base rows. I was hoping something like this would work but it still gets all of them.

var basicGear = db.Gear.OfType<Gear>();

Answer 1

尝试

var basicGear = db.Gear.Where(g => !(g is Weapon || g is Armor));

Answer 2

Since you want all the rows that aren't specifically Weapons or Armour. Generally, I would say you could try using the Except method .

var weapons = db.Gear.OfType<Weapon>(); // Gets just weapons.
var armor = db.Gear.OfType<Armor>(); // Gets just armor.
var allOtherStuff = db.Gear.Except(weapons).Except(armor);

Or even

var allOtherStuff = db.Gear.Except(weapons.Union(armor));

However, I'm not aware if Except has a translation to SQL within the Entity Framework (based on some answers on here they suggest it might not but this MSDN page would suggest it might).