Generic Entity Framework Read Method

Question

I'm new to Entity Framework and would like some help with my Read Methods.

I have this User class and its UserDAO with my methods.

I´ve already created

public IList<User> ReadUsersByName(string _name) {

var search = from m in context.Users
             where m.Name.Contains(_name)
             select m;

IList<User> _users = search.ToList();
return _users;
}

to search for Users by their name.

Other than Name, my Users have other attributes that I´d like to seach for (like their Age for example).

Do I need to replicate most of this code just changing "Name" for "Age"?

I´d like to create only one method and pass the Search Value AND Search Field by param. Is it possible?

You could make a method that uses reflection that takes the property name and search value in as parameters. — Matt Rowland, Jul 01 '16 at 19:11
Side note: Entity Framework and DAO is an awkward combination. — Gert Arnold, Jul 01 '16 at 22:08

score 1 · Accepted Answer · edited May 23 '17 at 11:58

1

You can pass where clauses into functions:

See this answer: C# Linq where clause as a variable

So, you could write something like this:

public IList<User> ReadUsersWhere(Expression<Func<User, bool>> whereClause) {
  return context.Users.Where(whereClause).ToList();
}

And you'd call it like this:

foo.ReadUsersWhere(u => u.Name.Contains("Joe"));

But at that point, you're basically just exposing an IQueriable/reinventing the wheel.

edited May 23 '17 at 11:58

Community

1
1

answered Jul 01 '16 at 20:05

Christopher Davies

4,461
2
34
33

Thank you very much. That is exactly what I was looking for. – ThalesMiguel Jul 01 '16 at 20:17

Generic Entity Framework Read Method

1 Answers1