LINQ statement in my project always returns null, is there anything I'm doing wrong?

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Hi All ,

I have the following method in in my c# project

C#

public string GetUser(){

var t = context.UsersTable.firstOrDefault(x =>x.Id = 2);
return t.Username


}

Just as simple as that ! but t is always null. user with id of 2 exists in the database i know that for a fact. What am i doing wrong?

What I have tried:

I ahve tried debugging and nowi 'm stuck but trying to understand on where i'm going wrong

Posted 7-Jun-16 4:02am

1Future

Updated 7-Jun-16 5:16am

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Comments

Karthik_Mahalingam 7-Jun-16 10:07am

means UsersTable doesn't have the row with id as 2, check in database.

Richard Deeming 7-Jun-16 10:13am

Either that's not the code you have in your project, or your project doesn't compile.

It's FirstOrDefault, not firstOrDefault; C# is case-sensitive.

You're missing a semi-colon on the return line.

And it should be x.Id == 2, not x.Id = 2. The equality operator requires two "=" signs.

Also, FirstOrDefault can return null if there are no matching items. If that happens, the return t.Username line will throw a NullReferenceException.

1Future 7-Jun-16 10:13am

it does have the id of 2 . thats what weird

Karthik_Mahalingam 7-Jun-16 10:53am

Apply breakpoint and Check the table rows count

CHill60 7-Jun-16 10:27am

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Dave Kreskowiak · Accepted Answer · 2016-06-07T05:16:00

As Richard said above, the code should be:

C#

public string GetUser()
{
    var t = context.UsersTable.FirstOrDefault(x => x.Id == 2);
    return t.Username;
}

Of course, this assumes you even have data in the UsersTable in your database AND it assumes there is a User in the UsersTable with an Id of 2.

This code also assumes that every row in the UsersTable in the database has a Username.

Your code also makes the assumption that an object is returned without checking for it. If there is no object returned from the database your return statement will throw a "NullReferenceExeception".

An updated version of the code:

C#

public string GetUser(int userId)
{
    var t = context.UsersTable.FirstOrDefault(x => x.Id == userId);

    if (t == null)
    {
        // Returns an empty string if no User was found. You may want to 
        // change this to something more appropriate or have it throw 
        // an Exception of some kind, depending on your business rules.
        return string.Empty; 
    }
    else
    {
        // Returns the Username of the located userId.
        return t.Username;
    }
}