Hi Every one!
I want to fetch array of values of a single column in a table, for example, I have a table named Customer(ID,Name), and want to fetch ids of all customers. my query in LINQ is:
var ids = db.Customers.Select(c=>c.ID).ToList();
The answer of this query is correct, but I ran SQL Server Profiler, and saw the query which was like this:
SELECT [t0].[ID], [t0].[Name] FROM [dbo].[Customer] AS [t0]
I understood that LINQ selects all columns and then creates the integer array of ID fields.
How can I write a LINQ query which generates this query in SQL Server:
SELECT [t0].[ID] FROM [dbo].[Customer] AS [t0]
Thank you.
UPDATE: i have a function for doing this, and this function causes that result:
public static List<TResult> GetSingleColumn<T, TResult>(Func<T, bool> predicate, Func<T, TResult> select) where T : class
{
using (var db = new DBModelDataContext())
{
var q = db.GetTable<T>().AsQueryable();
if (predicate != null)
q = q.Where(predicate).AsQueryable();
return q.Select(select).ToList();
}
}
and use it like this:
var ids = DBMH.GetSingleColumn<Customer, int>(null, c => c.ID);