Find size of EntitySet?

Question

I have an entity set that looks like this when I print it to the console:

EntitySet {entityContext: resource_dbEntities, _expression: undefined, elementType: function, person: function, createNew:function…}

_defaultType: function person(){
_expression: EntitySetExpression

collectionName: "person"

createNew: function person(){
elementType: function person(){
entityContext: resource_dbEntities

eventHandlers: undefined

name: "person"

person: function person(){
roles: undefined

stateManager: EntityStateManager

tableName: "person"

tableOptions: undefined

__proto__: EntitySet

Is there a way to find out how many elements are in the entityset? I'm not sure it's being populated but am unsure how to check.

Something like "myEntitySet.size"?

Answer 1

If you're querying against the whole database anyway, as you mentioned in your comment, you can go with querying the DbSet's Count, even though that will fetch all rows from the database.

static void Main(string[] args)
    {
        using (var context = new EntityContext())
        {
            context.Entities.Add(new MyEntity());
            context.Entities.Add(new MyEntity());
            var myEntityCount = context.Entities.Count();
            Console.WriteLine("The context now tracks {0} entities", context.Entities.Local.Count);
            context.SaveChanges();
        }

        using (var context = new EntityContext())
        {
            Console.WriteLine("The db had {0} entities when I queried it", context.Entities.Count());
            context.SaveChanges();
        }
    }

class MyEntity
{
    public int MyEntityId { get; private set; }
}

class EntityContext:DbContext
{
    public DbSet<MyEntity> Entities { get; set; }
}

With large amount of data in your db, you wouldn't want to do that, and you will have to resort to writing sql to return just the count of the table, without fetching everything.