<\/div>\n

Merhaba,<\/p>\n

.NET Core \u00e7ekirde\u011finde geli\u015ftirilen bir projede veritaban\u0131 i\u015flemlerinizi Class Library olarak ayr\u0131 bir katmanda ger\u00e7ekle\u015ftirmek istiyor olabilirsiniz. Lakin bu iste\u011finize istinaden gerekli i\u015flemleri yapt\u0131ktan sonra migration olu\u015ftururken “Unable to create an object of type ‘Context’. For the different patterns supported at design time, see…<\/em>” hatas\u0131yla kar\u015f\u0131la\u015f\u0131yor olabilirsiniz. E\u011fer ki, bahsedilen hatay\u0131 ald\u0131ysan\u0131z ve hala bir \u00e7\u00f6z\u00fcm aray\u0131\u015f\u0131ndaysan\u0131z do\u011fru adrestesiniz. \u015eimdi gelin bu hataya tak\u0131lmaks\u0131z\u0131n Class Library’de veritaban\u0131 i\u015flemlerini nas\u0131l yapaca\u011f\u0131m\u0131z\u0131 inceleyelim.<\/p>\n

\u0130\u00e7eri\u011fimizde k\u00fc\u00e7\u00fck bir senaryo \u00fczerinden gidece\u011fimizden dolay\u0131 ilk olarak veritaban\u0131 i\u015flemlerini yapaca\u011f\u0131m\u0131z Class Library’de gerekli olan “Context” ve “Entity” yap\u0131lar\u0131n\u0131 olu\u015ftural\u0131m.<\/p>\n

\r\n    public class VTContext : DbContext\r\n    {\r\n        public VTContext(DbContextOptions<VTContext> options) : base(options)\r\n        {\r\n        }\r\n        public DbSet<Employee> Employees { get; set; }\r\n        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)\r\n        {\r\n            optionsBuilder.UseSqlServer("Server=.;Database=NewDatabase;Trusted_Connection=True;");\r\n        }\r\n    }\r\n<\/pre>\n\r\n    public class Employee\r\n    {\r\n        public int Id { get; set; }\r\n        public string Name { get; set; }\r\n        public int Age { get; set; }\r\n    }\r\n<\/pre>\nGerekli “Context” ve “Entity” yap\u0131lar\u0131 olu\u015fturulduktan sonra s\u0131ra migrationlar\u0131 olu\u015fturmaya geldi. Bunun i\u00e7in Class Library projesinin dizininde a\u015fa\u011f\u0131daki ekran g\u00f6r\u00fcnt\u00fcs\u00fcnde oldu\u011fu gibi migration talimatlar\u0131n\u0131 vermemiz yeterli…<\/p>\n
<\/a><\/p>\n
\u0130\u015fte… G\u00f6r\u00fcld\u00fc\u011f\u00fc \u00fczere i\u00e7eri\u011fimizin ilk paragraf\u0131nda de\u011findi\u011fimiz ilgili hatayla kar\u015f\u0131la\u015fm\u0131\u015f bulunmaktay\u0131z.<\/p>\n
Bu hata, olu\u015fturdu\u011fumuz “VTContext” isimli kaynak ad\u0131nda bir nesneyi olu\u015fturacak tasar\u0131m\u0131n olmamas\u0131ndan kaynaklanmaktad\u0131r. Bunun i\u00e7in bizim bir strateji belirlememiz gerekecektir. O da \u015f\u00f6yledir;<\/p>\n
\r\n    public class DesignTimeDbContextFactory : IDesignTimeDbContextFactory<VTContext>\r\n    {\r\n        public VTContext CreateDbContext(string[] args)\r\n        {\r\n            var builder = new DbContextOptionsBuilder<VTContext>();\r\n            var connectionString = "Server=.;Database=NewDatabase;Trusted_Connection=True;";\r\n            builder.UseSqlServer(connectionString);\r\n            return new VTContext(builder.Options);\r\n        }\r\n    }\r\n<\/pre>\nBu s\u0131n\u0131f\u0131 context ile ayn\u0131 dizinde olu\u015fturmam\u0131z yeterlidir. Tek yap\u0131lmas\u0131 gereken bulundu\u011fu projeyi bir seferli\u011fine Build etmektir. \u0130lgili s\u0131n\u0131f\u0131 incelersek e\u011fer; “IDesignTimeDbContextFactory” interface’i sayesinde “CreateDbContext” isimli bir metodu implement etmekte ve i\u00e7erik olarak Factory Method Design Pattern<\/a>‘i kullanarak bizlere belirtilen tipte context nesnesi \u00fcretmektedir. <\/p>\n
Dolay\u0131s\u0131yla bu durumda tekrar migration talimat\u0131n\u0131 verirsek;
\n<\/a>
\nekran g\u00f6r\u00fcnt\u00fcs\u00fcnden anla\u015f\u0131laca\u011f\u0131 \u00fczere migration sorunsuz bir \u015fekilde ba\u015far\u0131yla olu\u015fturulacakt\u0131r. Hatta olu\u015fturulan t\u00fcm migrasyonlar veritaban\u0131na yans\u0131t\u0131larak veritaban\u0131 olu\u015fturulmu\u015f ve tablolar bas\u0131lm\u0131\u015ft\u0131r.
\n<\/a><\/p>\n
G\u00f6rd\u00fc\u011f\u00fcn\u00fcz \u00fczere .NET Core projelerinde veritaban\u0131 i\u015flemlerinizi bu \u015fekilde Class Library’e alabilir ve micro service tad\u0131nda \u00e7al\u0131\u015fmalar\u0131n\u0131za devam edebilirsiniz.<\/p>\n
\u0130lgilenenlerin faydalanmas\u0131 dile\u011fiyle…
\nSonraki yaz\u0131lar\u0131mda g\u00f6r\u00fc\u015fmek \u00fczere…
\n\u0130yi \u00e7al\u0131\u015fmalar…<\/p>\n","protected":false},"excerpt":{"rendered":"
Merhaba, .NET Core \u00e7ekirde\u011finde geli\u015ftirilen bir projede veritaban\u0131 i\u015flemlerinizi Class Library olarak ayr\u0131 bir katmanda ger\u00e7ekle\u015ftirmek istiyor olabilirsiniz. Lakin bu iste\u011finize istinaden gerekli i\u015flemleri yapt\u0131ktan sonra migration olu\u015ftururken “Unable to create an object of...<\/p>\n","protected":false},"author":1,"featured_media":10242,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2739,2668,2656],"tags":[2664,2740,2741,2746,2745,260,484,2747],"class_list":["post-10233","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-net-core","category-asp-net-core-2","category-asp-net-core-2-mvc","tag-net-core","tag-net-core-hata","tag-net-core-hata-cozumu","tag-net-core-migrations","tag-class-library","tag-hata","tag-hata-cozumu","tag-idesigntimedbcontextfactory"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/10233","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=10233"}],"version-history":[{"count":6,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/10233\/revisions"}],"predecessor-version":[{"id":10243,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/10233\/revisions\/10243"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/media\/10242"}],"wp:attachment":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/media?parent=10233"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/categories?post=10233"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/tags?post=10233"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}