<\/div>\n
Merhaba,<\/p>\n
Bu i\u00e7eri\u011fimizde EF Core’un kal\u0131t\u0131msal durumlardaki davran\u0131\u015flar\u0131ndan olan Table Per Type(TPT) ve Table Per Hierarchy(TPH) modellemelerini inceliyor olaca\u011f\u0131z.<\/p>\n
Table Per Type(TPT) Nedir?<\/h3>\n
Veritaban\u0131 a\u00e7\u0131s\u0131ndan bir tablodaki belirli kolonlar\u0131n ba\u011f\u0131ms\u0131z olarak birebir ili\u015fki ile farkl\u0131 tablolarda tutulmas\u0131d\u0131r. Bunun i\u00e7in EF Core taraf\u0131nda, merkezi tabloyu temsil eden bir t\u00fcrle\/s\u0131n\u0131fla kal\u0131t\u0131msal hiyerar\u015fide olan entity s\u0131n\u0131flar\u0131 olu\u015fturularak, ana s\u0131n\u0131f\/base class dahil t\u00fcm alt s\u0131n\u0131flara kar\u015f\u0131l\u0131k bir tablo generate edilmesiyle sa\u011flanan davran\u0131\u015ft\u0131r.<\/p>\n
Misal olarak a\u015fa\u011f\u0131daki, bir \u00fcr\u00fcn bilgisine kar\u015f\u0131l\u0131k olu\u015fturulan s\u0131n\u0131flar\u0131n modellemesini ele al\u0131rsak e\u011fer;<\/p>\n
\r\npublic class ApplicationUser\r\n{\r\n    public int Id { get; set; }\r\n    public string Name { get; set; }\r\n}\r\n<\/pre>\n<\/div>\n\n\r\npublic class Student : ApplicationUser\r\n{\r\n    public string School { get; set; }\r\n}\r\n<\/pre>\n<\/div>\n\n\r\npublic class Teacher : ApplicationUser\r\n{\r\n    public string Branch { get; set; }\r\n}\r\n<\/pre>\n<\/div>\nG\u00f6r\u00fcld\u00fc\u011f\u00fc \u00fczere esas\u0131nda t\u00fcm entity’ler bir tane kullan\u0131c\u0131ya kar\u015f\u0131l\u0131k gelecek tek bir veri tutmak i\u00e7in tasarlanm\u0131\u015ft\u0131r. Haliyle b\u00f6yle bir durumda bu entity’leri context nesnesine a\u015fa\u011f\u0131daki \u015fekilde bildirmemiz Table Per Type<\/em> davran\u0131\u015f\u0131n\u0131 sergilememizi sa\u011flayacakt\u0131r.<\/p>\n
\n\r\npublic class TPTExampleDb : DbContext\r\n{\r\n    .\r\n    .\r\n    .\r\n\r\n    public DbSet<ApplicationUser> Users { get; set; }\r\n    public DbSet<Student> Students { get; set; }\r\n    public DbSet<Teacher> Teachers { get; set; }\r\n    protected override void OnModelCreating(ModelBuilder modelBuilder)\r\n    {\r\n        \/\/Table Per Type(TPT)\r\n        modelBuilder.Entity<Student>().ToTable("StudentUsers");\r\n        modelBuilder.Entity<Teacher>().ToTable("TeacherUsers");\r\n    }\r\n}\r\n<\/pre>\n<\/div>\nDikkat ederseniz e\u011fer t\u00fcm entity’ler DbSet olarak eklenmi\u015f lakin alt modeller ise OnModelCreating<\/code> i\u00e7erisinde ToTable<\/code> olarak nitelendirilerek konfig\u00fcre edilmi\u015ftir. Bu \u00e7al\u0131\u015fman\u0131n neticesinde migration olu\u015fturup veritaban\u0131n\u0131 update edersek a\u015fa\u011f\u0131daki gibi bir tablo yap\u0131lanmas\u0131n\u0131n kuruldu\u011funu g\u00f6rece\u011fiz.<\/a>Unutulmamal\u0131d\u0131r ki, t\u00fcm alt s\u0131n\u0131flara kar\u015f\u0131l\u0131k Table Per Type<\/em> davran\u0131\u015f\u0131nda birebir ili\u015fkide tablolar olu\u015fturulabilmesi i\u00e7in yukar\u0131daki gibi ToTable<\/code> ile isimlendirilmeleri gerekmektedir. Bu zaruridir.<\/p>\n
Peki hoca, Table Per Type davran\u0131\u015f\u0131nda CRUD i\u015flemlerini nas\u0131l yapaca\u011f\u0131z?<\/em><\/strong> \u015feklinde sorunuzu duyar gibiyim… Tabi ki de bunu g\u00f6stermeden ge\u00e7meyece\u011fiz \ud83d\ude42<\/p>\n
Bunun i\u00e7in tek yap\u0131lmas\u0131 gereken CRUD i\u015flemleri s\u00fcrecinde sadece alt s\u0131n\u0131flar\u0131 kullanmakt\u0131r.<\/p>\n
\n\r\nusing TPTExampleDb context = new();\r\nawait context.Students.AddAsync(new() { Name = "Hilmi", School = "Yozgat Ticaret Meslek Lisesi" });\r\nawait context.Students.AddAsync(new() { Name = "Furkan", School = "Ka\u015f\u0131k\u00e7\u0131 Torna Tesviye Meslek Lisesi" });\r\nawait context.Students.AddAsync(new() { Name = "Ali", School = "B\u00fclb\u00fclderesi Anadolu Meslek Lisesi" });\r\nawait context.Teachers.AddAsync(new() { Name = "Emrah", Branch = "Matematik" });\r\nawait context.Teachers.AddAsync(new() { Name = "Engin", Branch = "M\u00fczik" });\r\nawait context.Teachers.AddAsync(new() { Name = "Erol", Branch = "Dayak" });\r\nawait context.SaveChangesAsync();\r\n<\/pre>\n<\/div>\n<\/a>Dikkat ederseniz e\u011fer verileri ‘Id’ kolonu \u00fczerinden birebir olan bir ili\u015fkide tutmaktad\u0131r.
\nAyn\u0131 \u015fekilde veri okumak istedi\u011finizde de ilgili alt s\u0131n\u0131f\u0131 sorgulayabilirsiniz.
\n<\/a><\/p>\n
Table Per Type yakla\u015f\u0131m\u0131nda hiyerar\u015fik olarak ne kadar entity varsa o kadar derinlikte birebir ili\u015fkili tablo olu\u015fturulacakt\u0131r.<\/em><\/p><\/blockquote>\n
Ayr\u0131ca son olarak ‘Users’ DbSet’i \u00fczerinden sorgulama yaparken sorguyu alt t\u00fcre indirgemek istiyorsan\u0131z e\u011fer a\u015fa\u011f\u0131daki gibi OfType<\/code> metodundan istifade edebilirsiniz.<\/p>\n
\n\r\nvar users = await context.Users.ToListAsync();\r\nvar students = users.OfType<Student>().ToList();\r\nvar teachers = users.OfType<Teacher>().ToList();\r\n<\/pre>\n<\/div>\nTable Per Hierarchy (TPH) Nedir?<\/h3>\nBu davran\u0131\u015fta ise hiyerar\u015fi i\u00e7indeki t\u00fcm entity’ler i\u00e7in tek bir tablo olu\u015fturulmakta ve bu tabloda veriler tutulurken ortak olan yani base class’dan gelen alanlar doldurulmakta, olmayan alanlar i\u00e7in nullable \u015fart\u0131 gelmektedir. Yani bir ba\u015fka deyi\u015fle, veritaban\u0131ndaki bir tablo EF Core taraf\u0131nda birden fazla entity’nin b\u00fct\u00fcnsel haline kar\u015f\u0131l\u0131k gelmektedir diyebiliriz.<\/p>\n
Bu davran\u0131\u015fa da \u00f6rnek mahiyetinde yine yukar\u0131daki entity’lerden yola \u00e7\u0131karsak e\u011fer context nesnesi a\u015fa\u011f\u0131daki gibi tasarlanacakt\u0131r;<\/p>\n\n\r\npublic class TPHExampleDb : DbContext\r\n{\r\n    .\r\n    .\r\n    .\r\n\r\n    public DbSet<ApplicationUser> Users { get; set; }\r\n    public DbSet<Student> Students { get; set; }\r\n    public DbSet<Teacher> Teachers { get; set; }\r\n}\r\n<\/pre>\n<\/div>\nDikkat ederseniz Table Per Hierarchy<\/em> davran\u0131\u015f\u0131 i\u00e7in OnModelCreating<\/code> i\u00e7erisinde herhangi bir i\u015flem yapmaya gerek yoktur. Hiyerar\u015fik olarak tasarlanan t\u00fcm entity’lerin direkt olarak DbSet t\u00fcr\u00fcnde tan\u0131mlanmas\u0131 yeterlidir. Bu tan\u0131mlamadan sonra OnModelCreating<\/code> i\u00e7erisinde ToTable<\/code> i\u015flemi yaparsak bu Table Per Type<\/em> davran\u0131\u015f\u0131na y\u00f6nlenecektir.<\/p>\nBu vaziyette migration olu\u015fturup, veritaban\u0131n\u0131 g\u00fcncellersek e\u011fer a\u015fa\u011f\u0131daki gibi bir tablo olu\u015fturulacakt\u0131r.
\n<\/a>Bu tabloda g\u00f6r\u00fcld\u00fc\u011f\u00fc \u00fczere \u00fcst s\u0131n\u0131fla birlikte t\u00fcm alt s\u0131n\u0131flardaki property’ler tek bir tabloya kolon olarak eklenmi\u015f vaziyettedir.<\/p>\n
\u015eimdi buradan anla\u015f\u0131lan, ister ‘Student’ ister ‘Teacher’ verileri gelsin her ikisi de bu olu\u015fturulan ‘Users’ tablosuna eklenecektir. Hal b\u00f6yleyken gelecek olan verinin hangi entity’e \u00f6zel oldu\u011funu ayr\u0131\u015ft\u0131rabilmek i\u00e7in EF Core taraf\u0131ndan eklenen Discriminator<\/strong><\/span> kolonunu g\u00f6rmekteyiz. Bu kolonda gelen verinin hangi entity taraf\u0131ndan kay\u0131t edildi\u011fine dair bilgi tutulacakt\u0131r.<\/p>\n
\u015e\u00f6yle ki;<\/p>\n
\n\r\nusing TPHExampleDb context = new();\r\nawait context.Students.AddAsync(new() { Name = "Hilmi", School = "Hac\u0131 H\u00fcseyin \u0130mam Hatip Lisesi" });\r\nawait context.Students.AddAsync(new() { Name = "Rauf", School = "Laylaylom Galiba Sana G\u00f6re Sevmeler Lisesi" });\r\nawait context.Teachers.AddAsync(new() { Name = "Emine", Branch = "Fizik" });\r\nawait context.Teachers.AddAsync(new() { Name = "Muiddin", Branch = "Edebiyat" });\r\nawait context.SaveChangesAsync();\r\n<\/pre>\n<\/div>\n\u015feklinde veri ekledi\u011fimizde a\u015fa\u011f\u0131daki ekran g\u00f6r\u00fcnt\u00fcs\u00fcnde oldu\u011fu gibi hangi datan\u0131n hangi entity’den geldi\u011fini ‘Discriminator’ kolonuna eklemekte ve ilgili t\u00fcr\u00fcn d\u0131\u015f\u0131ndaki alana null kar\u015f\u0131l\u0131\u011f\u0131n\u0131 vermektedir.<\/a>Sorgularken de yine direkt t\u00fcrler \u00fczerinden sorgulama yap\u0131labilece\u011fi gibi<\/p>\n
\n\r\nvar students = await context.Students.ToListAsync();\r\nvar teachers = await context.Teachers.ToListAsync();\r\n<\/pre>\n<\/div>\nOfType<\/code> fonksiyonu e\u015fli\u011finde de alt t\u00fcre indirgeyerek sorgulayabilirsiniz.<\/p>\n\n\r\nvar students =  context.Users.OfType<Student>();\r\nvar teachers =  context.Users.OfType<Teacher>();\r\n<\/pre>\n<\/div>\nHer iki \u015fekilde de ilgili tablodan entity t\u00fcr\u00fcne \u00f6zg\u00fc veriler ayr\u0131\u015ft\u0131r\u0131larak, getirilecektir.<\/p>\nTable Per Hierarchy yakla\u015f\u0131m\u0131nda hiyerar\u015fik olarak entity derinli\u011fi fark etmeksizin t\u00fcm t\u00fcrler tek bir tabloya yans\u0131t\u0131lacak ve aralar\u0131ndaki fark ‘Discriminator’ kolonu sayesinde ayr\u0131\u015ft\u0131r\u0131lacakt\u0131r.<\/em><\/p><\/blockquote>\n
Nihai olarak,
\nEntity’ler aras\u0131ndaki kal\u0131t\u0131msal durum s\u00f6z konusuyken; Table Per Type<\/em>, her tip\/entity’e kar\u015f\u0131l\u0131k bir tablo davran\u0131\u015f\u0131 sergilerken, Table Per Hierarchy<\/em> ise her hiyerar\u015fiye kar\u015f\u0131l\u0131k bir tablo davran\u0131\u015f\u0131n\u0131 sergilemektedir.<\/p>\n
\u0130lgilenenlerin faydalanmas\u0131 dile\u011fiyle…
\nSonraki yaz\u0131lar\u0131mda g\u00f6r\u00fc\u015fmek \u00fczere…
\n\u0130yi \u00e7al\u0131\u015fmalar…<\/p>\nNot : Makale s\u00fcrecinde kullan\u0131lan kodlar\u0131n kaynaklar\u0131n\u0131 a\u015fa\u011f\u0131daki Githup adreslerinden edinebilirsiniz.
\nEF Core Table Per Type<\/a>
\nEF Core Table Per Hierarchy<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
Merhaba, Bu i\u00e7eri\u011fimizde EF Core’un kal\u0131t\u0131msal durumlardaki davran\u0131\u015flar\u0131ndan olan Table Per Type(TPT) ve Table Per Hierarchy(TPH) modellemelerini inceliyor olaca\u011f\u0131z. Table Per Type(TPT) Nedir? Veritaban\u0131 a\u00e7\u0131s\u0131ndan bir tablodaki belirli kolonlar\u0131n ba\u011f\u0131ms\u0131z olarak birebir ili\u015fki ile...<\/p>\n","protected":false},"author":1,"featured_media":11538,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4446,2914],"tags":[2851,4564,4560,4565,4561,4562,4558,4563,4559],"class_list":["post-24821","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-net-6","category-entity-framework-core","tag-ef-core","tag-ef-core-table-per-hierarchy","tag-ef-core-table-per-type","tag-ef-core-tph","tag-ef-core-tpt","tag-table-per-hierarchy","tag-table-per-type","tag-tph","tag-tpt"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/24821","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/comments?post=24821"}],"version-history":[{"count":42,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/24821\/revisions"}],"predecessor-version":[{"id":24869,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/24821\/revisions\/24869"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/media\/11538"}],"wp:attachment":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/media?parent=24821"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/categories?post=24821"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/tags?post=24821"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}