// NMemory

// Doc: https://nmemory.net/query-data

​

// @nuget: NMemory

​

using System;

using System.Linq;

using NMemory;

using NMemory.Indexes;

using NMemory.Tables;

public class Program

{

    public static void Main()

    {

        MyDatabase myDatabase = new MyDatabase();

​

        myDatabase.Groups.Insert(new Group() { Id = 1, Name = "Group_1"});

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        myDatabase.Groups.Insert(new Group() { Id = 2, Name = "Group_2"});

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        myDatabase.Members.Insert(new Member() { Id = 1, GroupId = 1, Name = "It's Member_1" });

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        myDatabase.Members.Insert(new Member() { Id = 2, Name = "It's Member_2" });

​

​

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        var query =

            from p in myDatabase.Members

            join g in myDatabase.Groups on p.GroupId equals g.Id

            select new { Name = p.Name, Group = g.Name };

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        FiddleHelper.WriteTable("Members With Groups",query.ToList());

​

​

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        var groups = myDatabase.Groups.ToList();

        var members = myDatabase.Members.ToList();

        FiddleHelper.WriteTable("All Groups",groups);

        FiddleHelper.WriteTable("All Members",members);

    }

    public class MyDatabase : Database

    {

        public MyDatabase()

        {

            var members = this.Tables.Create<Member, int>(x => x.Id);

            var groups = base.Tables.Create<Group, int>(g => g.Id);

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            this.Members = members;

            this.Groups = groups;

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            RelationOptions options = new RelationOptions(

                cascadedDeletion: true);

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            var peopleGroupIdIndex = members.CreateIndex(

                new RedBlackTreeIndexFactory(),

                p => p.GroupId);

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            this.Tables.CreateRelation(

                groups.PrimaryKeyIndex,

                peopleGroupIdIndex,

                x =>  x ?? -1,

                x => x,

                options);

        }

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        public ITable<Member> Members { get; private set; }

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        public ITable<Group> Groups { get; private set; }

    }

​

    public class Member

    {

        public int Id { get; set; }

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        public string Name { get; set; }

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        public int? GroupId { get; set; } 

    }

​

    public class Group

    {

        public int Id { get; set; } 

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        public string Name { get; set; }

​

    }

}