Using Entity Framework Efficiently

Question

I'm using Entity framework in my ASP.NET MVC project. I need to know that if I'm dealing correctly with the following scenario.

Lets say my Employee table has over 100000 records and I have to apply various filtering according to the client requirement.

So I write 1 method ReadAll() to retrieve all the records from the database and then apply filtering to the datasource using lambda expressions.

Ex: Get employee by ID

public List<Employee> ReadAll()
{
   // return List<Employee>
} 


private Employee(int id)
{
   Employee obj=ReadAll().where(o=>o.empID == id).First();
}

I'm trying to use one read all method because there are various filtering to be applied and I do not have to write separate database access methods to each of them.

Will this affect my application performance adversely?

Answer 1

Change ReadAll to return IQueryable so that it won't execute the query until after you've applied your filter and called First() or ToList().

public IQueryable<Employee> ReadAll()
{
   // return List<Employee>
} 

Entity Framework uses a concept called deferred execution . I encourage you to read up on it.