Question

I am trying to select an entity of type Member with this code in C#. I was watching a video tutorial and they do it just the same, but it doesn’t work for me.

        Member member = new Member();
        var query =  from m in db.Members  where Member.MemberID == textBox1.Text 
        select m;     
        var currentMember =  query.FirstOrDefault();
        string CurrentID = M.MemberID;    

There are no exceptions or stuff, but I get all of the currentMember’s properties are null.
Any ideas to get the expected result?

Answer 1

I think you might be mixing up your variables a little bit here. Let’s try to clean this code up:

var memberQuery = from m in db.Members
                  where m.MemberID == textBox1.Text
                     // ^ you need to reference the MemberID by the query
                     //   variable (m) not the class name (Member).
                  select m;

var member = memberQuery.SingleOrDefault();
                      // ^ when you only expect zero or one records from the
                      //   database, use SingleOrDefault instead of
                      //   FirstOrDefault, because it will throw an exception
                      //   when more than one record is returned.

if (member != null)
 // ^ always check to make sure that the database returned a value before trying
 //   to access any fields on the object.
{
    string currentId = member.MemberID;
}
else
{
    // a member with the given ID doesn't exist in the database
}