ef-fluent-api

问题 I have an ArticleComment entity as you can see below: public class ArticleComment { public int ArticleCommentId { get; set; } public int? ArticleCommentParentId { get; set; } //[ForeignKey("ArticleCommentParentId")] public virtual ArticleComment Comment { get; set; } public DateTime ArticleDateCreated { get; set; } public string ArticleCommentName { get; set; } public string ArticleCommentEmail { get; set; } public string ArticleCommentWebSite { get; set; } public string AricleCommentBody {

问题 I'm trying to set up a one to many relationship in Entity Framework Core using the Fluent API with no success. I have two objects called Message and Source and are defined as public class Message { public int ID { get; set; } public int FromUserID { get; set; } public int ToUserID { get; set; } public int SourceID { get; set; } public int Priority { get; set; } public string Subject { get; set; } public string MessageBody { get; set; } public DateTime DateTimeCreated { get; set; } public

问题 I'm using EntityFramework Core, Code First and Fluent Api to define model database, and i've follow situation about strategy of map inheritance: public class Person { public int Id { get; set; } public string Name { get; set; } } public class User : Person { public string UserName { get; set; } public string Password { get; set; } } public class Employee : Person { public decimal Salary { get; set; } } public class Customer:Person { public long DiscountPoints { get; set; } } Business logical

问题 I defined a DataObject as: public class SensorType : EntityData { //PKs public string CompanyId { get; set; } public string ServiceId { get; set; } public string Type { get; set; } } And used fluent API to make CompanyId and ServiceId a composite key: modelBuilder.Entity<SensorType>() .HasKey(t => new { t.CompanyId, t.ServiceId }); //No autogeneration of PKs modelBuilder.Entity<SensorType>().Property(t => t.ServiceId) .HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema

问题 I defined a DataObject as: public class SensorType : EntityData { //PKs public string CompanyId { get; set; } public string ServiceId { get; set; } public string Type { get; set; } } And used fluent API to make CompanyId and ServiceId a composite key: modelBuilder.Entity<SensorType>() .HasKey(t => new { t.CompanyId, t.ServiceId }); //No autogeneration of PKs modelBuilder.Entity<SensorType>().Property(t => t.ServiceId) .HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema

来源： https://stackoverflow.com/questions/51308245/ef-core-2-1-self-referencing-entity-with-one-to-many-relationship-generates-add

来源： https://stackoverflow.com/questions/51308245/ef-core-2-1-self-referencing-entity-with-one-to-many-relationship-generates-add

问题 It seems use the Fluent API has more flexibility. So I choose the way to follow always use the Fluent API to determine the feature it have in db instead use the annotations to. But here is the problem,I couldn't find the way to set the Minimum length. Is there a method to perform this? And i notice,there are no much topic discuss this way.Is the Fluent API way popular?? Hope we choose the right side. 回答1: This is impossible at the moment with EF. If you really have to set a minimum length,

问题 I'm trying to create a multi-column unique index using a shadow property. I know I can solve this problem with just adding a property, but I would like to see if this is possible in a way to keep my model clean. To create a multi-column index you have the following option in Fluent API: modelBuilder.Entity<AlbumTrack>().HasIndex(t => new { t.TrackNumber, t.AlbumId).IsUnique(); But I don't want to clutter my model with an extra AlbumId property and thus would like to use a shadow property, for

问题 In EF Core 2.0, we have the ability to derive from IEntityTypeConfiguration for cleaner Fluent API mappings (source). How can I extend this pattern to utilize a base entity? In the example below, how can I have a BaseEntityConfiguration to reduce duplication in LanguageConfiguration and MaintainerConfiguration , modifying properties that are in the BaseEntity only in the BaseEntityConfiguration ? What would such a BaseEntityConfiguration look like; and how would it be used, if at all, in