I have two tables in the database one contains a list of all possible grocery values. For Example
Milk
Cheese
Bread
Meat
the second table contains Items from Grocery that are selected. For Example:
Milk
Cheese
I want开发者_如何学编程 a result that has all possible grocery items with Milk and Cheese selected.
Any ideas?
Here are the tables.
The GroceryList Table:
ID INT PK
Description Varchar(50)
The ShoppingList Table:
ID INT PK
GroceryListID int FK to GroceryList.ID
So the resulting Entity would be all items from GroceryList and if they exist in ShoppingList then selected is marked as true: ShoppingList.ID Grocerylists.Description Selected
Based on understanding you can do something like this
//first get the list of product which satisfy your condition
var ids = (from p ShoppingList
select p.GroceryListID ).ToList();
//second filter the Grocery products by using contains
var myProducts = from p in GroceryList
where ids.Contains(p.ID)
Select p;
or
if you want to get info about join than this image would help you
Inner Join
Outer Join
Try to understand and which may help you to resolve your query
Edit: Still sounds like you want to do a left join. In your case:
var LINQResult = from g in Datacontext.GroceryList
from s in DataContext.ShoppingList
.Where(c=>c.ID == g.ID)
.DefaultIfEmpty()
select new {
g.ID,
g.Description,
s.ID // Will be null if not selected.
};
For more examples:
Left Join on multiple tables in Linq to SQL
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