LINQ, select one item from one table, multiple items from another table - asp.net

Question

I am fairly new to using LINQ and are now trying to build a LINQ question I do not quite manage to solve.
I would like to ask a question to a database, where I want to bring back single rows from a few tables, but a list of rows from other tables.
See code below too see what I am trying to do:
public DB.store store { get; set; }
public List<DB.gallery_image> images { get; set; }
public List<DB.product> products { get; set; }
public static List<Store> getStoreInfo()
{
DBDataContext db = new DBDataContext();
var _dataToGet = from _store in db.stores
select new Store
{
store = _store,
images = (from a in db.gallery_images
where a.albumID == _store.storeID
select a).ToList(),
products = (from p in db.products
where p.storeID = _store.storeID).ToList()
};
return _dataToGet.ToList();
}
So I just want one row from "store" table, but a list from "images" and "product" tables.
The code above works fine, but is slow as hell.
I don't have any problems to select data from multiple tables as long as there is only one (or none) row per table, but when it is a list I'm having problem...

Answer 1

If I were you I would use deferred execution rather than materializing the queries with a call to ToList. I would change the data type of images and products to IEnumerable<> instead of List<>. Then I would not call ToList in the sub-queries because this results in a roundtrip to the database, hence, depending on how many stores you have it could turn into an extremely slow query.
You should see a performance gain here...
public DB.store store { get; set; }
public IEnumerable<DB.gallery_image> images { get; set; }
public IEnumerable<DB.product> products { get; set; }
public static List<Store> getStoreInfo()
{
DBDataContext db = new DBDataContext();
var _dataToGet = from _store in db.stores
select new Store
{
store = _store,
images = (from a in db.gallery_images
where a.albumID == _store.storeID
select a),
products = (from p in db.products
where p.storeID = _store.storeID)
};
return _dataToGet.ToList();
}