LINQ - joining multiple lists

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猫巷女王i
猫巷女王i 2021-01-21 14:33

I\'ve looked at the 101 Linq Samples here but I can\'t see anything like this in that list. If I\'m just not seeing a relevant example there, please link to it.

If I ha

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  •  [愿得一人]
    2021-01-21 15:07

    Not an explicit answer, but perhaps implicitly helpful building your system.

    Have you considered a richer domain model like so:

    class Student { int id; string name; IEnumerable enrolments }
    class Course { int id, string name; }
    class Enrolment { Student student; Course course; }
    

    ?

    The Student class could then have a method GetEnroledCourses() like so:

    public IEnumerable GetEnroledCourses()
    {
       return enrolements.Select(enrolement => enrolement.Course).ToList().AsReadonly();
    }
    

    A model that's merely a one-to-one mapping to the database suffice in some contexts, but if you have complex business logic such an «anemic domain model» might bite you.

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