Getting a NullpointerException on my code

Question

I am getting a Nullpointer on this code:

public void InsertImportantMsg (string msg, DateTime toDay, int visible)
    {

            connection.Open ();
            string query = "UPDATE IMPORTANTMESSAGE SET MESSAGES=':msg', DATETIME=':toDay', " +
                "LABELVISIBILITY=':visible'";
            connection.CreateCommand ();
            cmd.CommandText = query;
            cmd.Parameters.Add (":msg", msg);
            cmd.Parameters.Add (":toDay", toDay);
            cmd.Parameters.Add(":visible", visible);

            cmd.ExecuteNonQuery ();

    }

Specifically at this line:

cmd.CommandText = query;

I am passing the parameters right. Is there something wrong with my update statement, that I don't realize?

(I know the code should be in try catch, but it's on purpose for now, so don't look at that)

Thanks

possible duplicate of [What is a NullReferenceException and how do I fix it?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — Dirk, Oct 28 '14 at 11:36
are you missing: cmd = connection.CreateCommand(); line above? — Aurimas Neverauskas, Oct 28 '14 at 11:36
Are you *really* getting a `NullpointerException`? or are you getting a `NullReferenceException` ? — Marc Gravell, Oct 28 '14 at 11:38
A quick use of debug mode would show which object is null and likely why. — Allan S. Hansen, Oct 28 '14 at 11:38
dirk I know what a nullreference means, I just couldn't find it. aurimas-neverauskas thanks, that was it. Seemed so simple, but I was unable to locate it after looking at it for a long time. I don't know how I ended up deleting that — States, Oct 28 '14 at 11:39

score 1 · Answer 1 · answered Oct 28 '14 at 11:42

The immediate reason of the exception is that you haven't assigned cmd value. The implementtation could be like that

public void InsertImportantMsg (string msg, DateTime toDay, int visible) {
  connection.Open();

  // Put IDisposable into using...
  using (var cmd = connection.CreateCommand()) {
    // Format query to be readble
    cmd.CommandText = 
      @"UPDATE IMPORTANTMESSAGE
           SET MESSAGES = :msg, -- <- you don't need apostrophes here...
               DATETIME = :toDay,
               LABELVISIBILITY = :visible";

    cmd.Parameters.Add(":msg", msg);
    cmd.Parameters.Add(":toDay", toDay);

    //TODO: Check this - Oracle doesn't support boolean is SQL 
    cmd.Parameters.Add(":visible", visible);  

    cmd.ExecuteNonQuery(); 
  }
}

Yeah I know Oracle doesn't support boolean (unfortunately), but notice that visible is not a boolean value, but rather an int :D — States, Oct 28 '14 at 11:46

Getting a NullpointerException on my code

1 Answers1