■ LINQ를 사용해 데이터를 조회하는 방법을 보여준다.
▶ Group.cs
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namespace TestProject; /// <summary> /// 그룹 /// </summary> public class Group { //////////////////////////////////////////////////////////////////////////////////////////////////// Property ////////////////////////////////////////////////////////////////////////////////////////// Public #region ID - ID /// <summary> /// ID /// </summary> public int ID { get; set; } #endregion #region 명칭 - Name /// <summary> /// 명칭 /// </summary> public string Name { get; set; } #endregion } |
▶ Member.cs
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namespace TestProject; /// <summary> /// 회원 /// </summary> public class Member { //////////////////////////////////////////////////////////////////////////////////////////////////// Property ////////////////////////////////////////////////////////////////////////////////////////// Public #region ID - ID /// <summary> /// ID /// </summary> public int ID { get; set; } #endregion #region 성명 - Name /// <summary> /// 성명 /// </summary> public string Name { get; set; } #endregion #region 그룹 ID - GroupID /// <summary> /// 그룹 ID /// </summary> public int? GroupID { get; set; } #endregion } |
▶ Program.cs
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using NMemory; using NMemory.Indexes; using NMemory.Tables; namespace TestProject; /// <summary> /// 프로그램 /// </summary> class Program { //////////////////////////////////////////////////////////////////////////////////////////////////// Method ////////////////////////////////////////////////////////////////////////////////////////// Static //////////////////////////////////////////////////////////////////////////////// Private #region 프로그램 시작하기 - Main() /// <summary> /// 프로그램 시작하기 /// </summary> private static void Main() { Database database = new Database(); Table<Group , int> groupTable = database.Tables.Create<Group , int>(group => group.ID , null); Table<Member, int> memberTable = database.Tables.Create<Member, int>(member => member.ID, null); IIndex<Member, int?> memberGroupIDIndex = memberTable.CreateIndex(new RedBlackTreeIndexFactory(), member => member.GroupID); database.Tables.CreateRelation ( groupTable.PrimaryKeyIndex, memberGroupIDIndex, x => x ?? -1, x => x ); groupTable.Insert(new Group() { ID = 1, Name = "그룹 1"}); groupTable.Insert(new Group() { ID = 2, Name = "그룹 2"}); memberTable.Insert(new Member() { ID = 1, Name = "김철수", GroupID = 1 }); memberTable.Insert(new Member() { ID = 2, Name = "홍길동", GroupID = 1 }); memberTable.Insert(new Member() { ID = 3, Name = "홍삼수", GroupID = 1 }); memberTable.Insert(new Member() { ID = 4, Name = "김영희", GroupID = 2 }); memberTable.Insert(new Member() { ID = 5, Name = "이주희", GroupID = 2 }); var queryable = from m in memberTable join g in groupTable on m.GroupID equals g.ID select new { Name = m.Name, GroupName = g.Name }; foreach(var item in queryable) { Console.WriteLine($"{item.Name}, {item.GroupName}"); } } #endregion } |
