使用 Linq 进行多列选择

Question

I have the below SQL query. Not sure how to convert this to Linq.

select u.userid, u.firstname, u.lastname,companyname,city,state 
from user u 
order by  u.lastname, u.firstname

I've tried this:

public ActionResult Users() {
  dbEntities entities1 = new dbEntities();
  return View(from users in entities1.u_user select userid,firstname,lastname,companyname,city,state);
} 

Answer 1

The exact translation is :

Db.User.Select(p=> new {
    userid = p.userId,
    firstName = p.firstName,
    lastName = p.lastName,
    companyName p = p.companyName,
    city = p.City,
    state = p.State }).OrderBy(p=>p.lastName).ThenBy(p=>p.firstName)

Where you create a dynamic object containing only some fields you want.

If you want all properties of your entity, you can use simply :

Db.User.OrderBy(p=>p.lastName).ThenBy(p=>p.firstName)

Answer 2

In general, assuming C#, convert SQL to LINQ by converting phrases in LINQ comprehension syntax order, and if SQL has table aliases, use them in LINQ as range variables. Convert non-range functions like TOP or DISTINCT as function calls outside the rest of the expression.

var ans = from u in user
          orderby u.lastname, u.firstname
          select new { u.userid, u.firstname, u.lastname, u.companyname, u.city, u.state };