entity-framework

问题 Following this case, i'm trying to map a table column IsActive to two different entity property. is there any way to do this? 回答1: It is not possible. Each column must be mapped only once because otherwise it would lead to inconsistencies. For example if you would set different value to each property which one should be saved? Also having two properties exposing same field doesn't make sense. 回答2: You can't have two properties in the same Entity mapped to the same column. But there are

问题 Following this case, i'm trying to map a table column IsActive to two different entity property. is there any way to do this? 回答1: It is not possible. Each column must be mapped only once because otherwise it would lead to inconsistencies. For example if you would set different value to each property which one should be saved? Also having two properties exposing same field doesn't make sense. 回答2: You can't have two properties in the same Entity mapped to the same column. But there are

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

问题 I have a table column defined like this: ENTRY_STATUS NUMBER(2, 0) And in my EntityFramework class the respective field is defined like this: [Column("ENTRY_STATUS")] public int Status { get; set; } When checking the value to get an entry it works perfectly fine: var order = testDbContext.Orders.FirstOrDefault(o => o.Status > 1); But when I check the order entity after this statement it is always zero: if (order != null) { if (order.Status == 3) //Always Zero!!! { //Do something... } } What

问题 im new to entity framework , i created my entities from reverse engineering from a Mysql database that i have created in mysqlworkbench , and then i added some foreign keys in my entities and then i added a migration and tried to update my database but an error occured and it indicates that: "Table 'pidev.pidev.personal' doesn't exist". "pidev" is the name of my database. personal is a super class for two other subclasses "candiadte" and "employee" and im using TPH as inheritance strategy.

问题 im new to entity framework , i created my entities from reverse engineering from a Mysql database that i have created in mysqlworkbench , and then i added some foreign keys in my entities and then i added a migration and tried to update my database but an error occured and it indicates that: "Table 'pidev.pidev.personal' doesn't exist". "pidev" is the name of my database. personal is a super class for two other subclasses "candiadte" and "employee" and im using TPH as inheritance strategy.

问题 im new to entity framework , i created my entities from reverse engineering from a Mysql database that i have created in mysqlworkbench , and then i added some foreign keys in my entities and then i added a migration and tried to update my database but an error occured and it indicates that: "Table 'pidev.pidev.personal' doesn't exist". "pidev" is the name of my database. personal is a super class for two other subclasses "candiadte" and "employee" and im using TPH as inheritance strategy.

问题 I am trying to implement a simple self referencing relationship with EF 6.1.2 Code First. public class Branch { [Key] public int Id { get; set; } [Required] public string Name { get; set; } public int? ParentId { get; set; } [ForeignKey("ParentId")] public virtual Branch Parent { get; set; } public ICollection<Branch> Children { get; set; } // direct successors } In my application I have exactly one root branch. And except for this single root branch, every branch has exactly one parent (the

问题 I am trying to implement a simple self referencing relationship with EF 6.1.2 Code First. public class Branch { [Key] public int Id { get; set; } [Required] public string Name { get; set; } public int? ParentId { get; set; } [ForeignKey("ParentId")] public virtual Branch Parent { get; set; } public ICollection<Branch> Children { get; set; } // direct successors } In my application I have exactly one root branch. And except for this single root branch, every branch has exactly one parent (the