How can I write generic query in asp .net mvc for 3 different tables in db context with LINQ?

Question

I have 3 different tables and 3 different columns which are primary columns.

 public class Student
    {
        public int StudentId { get; set; }
        public string Name { get; set; }
    }

    public class Teacher
    {
        public int TeacherId { get; set; }
        public string Name { get; set; }
    }

    public class Lesson
    {
        public int LessonId { get; set; }
        public string Name { get; set; }
    }


var _context = new MyContext()

_context.Student(x=>x.StudentId == someValue)

or

_context.Teacher(x=>x.TeacherId == someValue)

or

_context.Lesson(x=>x.TeacherId == someValue)

only changing table name and key value.

What is the best way using generic method?

Faizan · Accepted Answer · 2018-04-07T10:18:37.200

0

Make a general repository and than inherit it with native repository of each class like this

public class GeneralRepository<T> where T : class
    {
        private MyContext Context = new MyContext();
        protected DbSet<T> Dbset { get; set; }
        public GeneralRepository()
        {
           Dbset = Context.Set<T>();
        }

    public T SelectByID(int? id)
    {
        var Record = Dbset.Find(id);
        return (Record);
    }

  public class StudentRepositoy :GeneralRepository<Student>
    {



    }

Make a object of native repositry and call the function

Where ever you need to call the function make a object of student repository

StudentRepositoy repository = new StudentRepositoy();
var result = repository.SelectByID(3);

edited Apr 07 '18 at 10:18

answered Apr 07 '18 at 09:47

Faizan

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5
16

Thanks. I just tried. but i says The entity type Student is not part of the model for the current context. – Maldio Robert Apr 07 '18 at 10:09
@MaldioRobert check it , I explained briefly – Faizan Apr 07 '18 at 10:19
https://stackoverflow.com/questions/20688922/the-entity-type-type-is-not-part-of-the-model-for-the-current-context – Faizan Apr 07 '18 at 10:24

score 0 · Answer 2 · answered Apr 07 '18 at 09:49

You can consider to use a pattern like "generic repository". Or you can simply write a method takes Expression> as input and pass the expression to it.

https://code.msdn.microsoft.com/generic-repository-pattern-ddea2262

https://www.codeproject.com/Articles/814768/CRUD-Operations-Using-the-Generic-Repository-Patte

How can I write generic query in asp .net mvc for 3 different tables in db context with LINQ?

2 Answers2