在Linq-to-SQL中从数据库读取数据

Question

I have this class:

public class Student1
{
            public String Name { set; get; }
            public String Number { set; get; }

            public List<String> TakedCourses  { set; get; }

            public List<String> PassedCourses = new List<String>();
}

and I use Linq-to-SQL to save students to the database.

Now I want to search a name in database and add all properties of this student to a new object of Student .

Like this:

Student s = new Student();
s = d.Students.Where(c => c.Name == cobStudents.SelectedItem.ToString()).Select(c => c);

it doesn't work and I don't know ho do this.

Thanks

Answer 1

Use FirstOrDefault it returns first matching element, Where returns all matching students collection ( not single element).

Student s = new Student(); 
s = d.Students.FirstOrDefault(c => c.Name
== cobStudents.SelectedItem.ToString());

You can even use SingleOrDefault if you are sure that condition true for only one element.

s = d.Students.SingleOrDefault(c => c.Name
== cobStudents.SelectedItem.ToString());

And then you could access using...

if(s!= null)
{
       // access s here.
}