IGroupingGetter<TModel> Interface

.NET Standard 2.x

Represents the getter for a group, where each row of data in the last level of the group corresponds to a TModel object. Used in conjunction with the grouping function of the DataStore.

When the IsGroup property is true, it is used to get a group of data; when the IsGroup property is false, you can access the Value property to get the data of a certain row.

Namespace: DWNet.Data

Assembly: DWNet.Data.dll

Syntax

public interface IGroupingGetter<TModel>;

Properties

Name	Return Type	Description
IsGroup	int	Whether the current IGroupingGetter object represents a group.
Key	object	When the IsGroup property is true, represents the common key of the objects in the current group.
Value	object	When IsGroup is false, gets a row of data.

Method

Name	Return Type	Description
GetEnumerator()	IEnumerator<IGroupingGetter<TModel>>	When the IsGroup property is true, returns an enumerator that iterates through the group.

Examples

The following code example creates an instance of GroupingGetter and receives data in a model object.

using Appeon.ApiDoc.Models;
using DWNet.Data;
using System;

namespace Appeon.ApiDoc.IGroupingGetter_GenericExamples
{
    public class IGroupingGetter_GenericExample
    {
        private readonly SchoolContext _context;

        public IGroupingGetter_GenericExample(SchoolContext context)
        {
            _context = context;
        }

        public void Example()
        {
            // Creates a datastore object
            IDataStore course = new DataStore("d_department_course", _context);

            course.Retrieve();

            var departmentGropup = course.GroupBy<D_Department_Course>();

            // Gets the grouped data of the first level
            foreach (var m in departmentGropup)
            {
                Console.WriteLine("Level1 Group key = {0}", m.Key);

                // Gets the grouped data of the second level
                foreach (var getter in m)
                {
                    Console.WriteLine(" Level2 Group key = {0}", getter.Key);

                    // Shows the Course_Title value in each group in a loop
                    foreach (var model in getter)
                    {                        
                        Console.WriteLine("  Course_Title = {0}", model.Value.Course_Title);
                    }
                   
                }
            }

            /*This code produces the following output:
            
            Level1 Group key = 1
             Level2 Group key = 1050
              Course_Title = Chemistry
              Course_Title = Chemistry
              Course_Title = Chemistry
             Level2 Group key = 1061
              Course_Title = Physics
              Course_Title = Physics
              Course_Title = Physics
              Course_Title = Physics
              Course_Title = Physics
              Course_Title = Physics
              Course_Title = Physics
            Level1 Group key = 2
             Level2 Group key = 2021
              Course_Title = Composition
              Course_Title = Composition
              Course_Title = Composition
              Course_Title = Composition
              Course_Title = Composition
             Level2 Group key = 2030
              Course_Title = Poetry
              Course_Title = Poetry
             Level2 Group key = 2042
              Course_Title = Literature
              Course_Title = Literature
              Course_Title = Literature
            
            */
        }
    }
}

Example Refer To

Model Class: D_Department_Course
DataWindow File: d_department_course