How do I improve the efficiency of the queries executed by this generic Linq-to-SQL data access clas
- by Lee D
Hi all,
I have a class which provides generic access to LINQ to SQL entities, for example:
class LinqProvider<T> //where T is a L2S entity class
{
DataContext context;
public virtual IEnumerable<T> GetAll()
{
return context.GetTable<T>();
}
public virtual T Single(Func<T, bool> condition)
{
return context.GetTable<T>().SingleOrDefault(condition);
}
}
From the front end, both of these methods appear to work as you would expect. However, when I run a trace in SQL profiler, the Single method is executing what amounts to a SELECT * FROM [Table], and then returning the single entity that meets the given condition. Obviously this is inefficient, and is being caused by GetTable() returning all rows.
My question is, how do I get the query executed by the Single() method to take the form SELECT * FROM [Table] WHERE [condition], rather than selecting all rows then filtering out all but one? Is it possible in this context?
Any help appreciated,
Lee
