[LINQ] Master–Detail Same Record (I)
- by JTorrecilla
PROBLEM Firstly, I am working on a project based on LINQ, EF, and C# with VS2010. The following Table shows what I have and what I want to show. Header C1 C2 C3 1 P1 01/01/2011 2 P2 01/02/2011 Details 1 1 D1 2 1 D2 3 1 D3 4 2 D1 5 2 D4 Expected Results 1 P1 01/01/2011 D1, D2, D3 2 P2 01/02/2011 D1,D4 IDEAS At the begin I got 3 possible ways: - Doing inside the DB: It could be achieved from DB with a CURSOR in a Stored Procedure. - Doing from .NET with LOOPS. - Doing with LINQ (I love it!!) FIRST APROX Example with a simple CLASS with a LIST: With and Employee Class that acts as Header Table: 1: public class Employee
2: {
3: public Employee () { }
4: public Int32 ID { get; set; }
5: public String FirstName{ get; set; }
6: public String LastName{ get; set; }
7: public List<string> Numbers{ get; set; } // Acts as Details Table
8: }
We can show all numbers contained by Employee:
1: List<Employee > listado = new List<Employee >();
2: //Fill Listado
3: var query= from Employee em in listado
4: let Nums= string.Join(";", em.Numbers)
5: select new {
6: em.Name,
7: Nums
8: };
The “LET” operator allows us to host the results of “Join” of the Numbers List of the Employee Class.
A little example.
ASAP I will post the second part to achieve the same with Entity Framework.
Best Regards
