CODEWITHSUNDEEP
c#wpfentity-framework
Peter B
Peter B

Reputation: 98

How to return a single value from a database?

I want to return the id(int) from the database without having to do it this way

var user = context.Users.FirstOrDefault(x => x.Username.Equals(username) && x.Password.Equals(password));
return user.UserID;

Currently I have something like this:

return context.Users.Where(x => x.Username.Equals(username) && x.Password.Equals(password))
                  .Select(x => x.UserID);

But I receive the following error:

Cannot convert expression type 'System.Linq.IQueryable<int>' to return type 'int'

Is it possible to do so? And if so how do I do it?

Appreciate the help!

Upvotes: 1

Views: 71

Answers (2)

Ali Humayun
Ali Humayun

Reputation: 1814

context.Users.Find(x=>x.Username.Equals(username) && x.Password.Equals(password)).UserID;

You will need to handle Null Exception.

Upvotes: 0

tschmit007
tschmit007

Reputation: 7800

you must materialize the result:

return context.Users.Where(x => x.Username.Equals(username) && 
    x.Password.Equals(password))
    .Select(x => x.UserID)
    .First(); // or FirstOrDefault(); // or .Single();

Upvotes: 2

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