ef-code-first

问题 I'm working on an ASP.NET MVC 6 project with Entity-Framework Core (version "EntityFramework.Core": "7.0.0-rc1-final" ) backed by a SQL Server 2012 express DB. I need to model a many-to-many relationship between a Person entity and an Address entity. As per this guide I modeled it with a PersonAddress join-table entity, because this way I can store some extra info. My goal is to set-up my system this way: If a Person instance is deleted, all the related PersonAddress instances must be deleted

问题 I need help to clarify how EF Code First Migrations works on production machine. I've some entity classes and DbContext-derived class to access entities. Now, I want to perform these several things: when my application starts, it must create database, if database does not exists; then database schema must be adjusted to the model; if database was created just now, I want to create some indexes; also, if database was created just now, it must be seeded by some initial data; all of these things

问题 If I have the below class: public class Foo() { public int PropertyIWantUpdated {get; set;} public int PropertyIDontWantUpdated (get; set} public ICollection<Bar> Bars {get; set;} } When saving to my db, instead of context.Entry(thisFoo).State = EntityState.Modified; I'm using context.Entry(thisFood).Property(tf => tf.PropertyIWantUpdated).IsModified = true; how can I also save changes to Bars? 回答1: It depends what you are trying to update. First of all let me clarify one important fact - if

问题 I'm trying to update a Customer in my database using ASP.NET Web API and Entity Framework 5 code-first, but it's not working. My entities look like this: public class CustomerModel { public int Id { get; set; } public string Name { get; set; } // More fields public ICollection<CustomerTypeModel> CustomerTypes { get; set; } } public class CustomerTypeModel { public int Id { get; set; } public string Type { get; set; } [JsonIgnore] public ICollection<CustomerModel> Customers { get; set; } }

问题 In the code below, I need to set a foreign key constrant on ParentInfoAddProperties.ParentQuestionAnswersId so that it is dependent on ParentQuestionAnswers.Id (which is a Primary Key). I am attempting to do so using data annotations but Entity Framework 6 wants to create a new Foreign Key column in my ParentQuestionAnswers table which references the ParentInfoAddProperties.Id column not the ParentInfoAddProperties.ParentQuestionAnswersId column. I do not want Entity Framework to create a new

问题 I have a DbContext with set up different DbSet<T> s with all types that derive from the same base class: public class Foo : Entity { } public class Bar : Entity { } MyDbContext : DbContext { public DbSet<Foo> Foos { get; set; } public DbSet<Bar> Bars { get; set; } } Is it possible to get all entities which have the Entity base class in one query, like: DbContext.Set<Entity>(); // doesn't work I tried to introduce an explicit DbSet<Entity> to the DbContext, but that results in one big table

问题 I'm using Microsoft.AspNet.Identity 2.0.0-beta1 and Entity Framework 6.1.0-beta1 (released 11 Feb 2014). I'm getting the following error when I try to change the default type of User ID Primary Key from string to int AND when I try to use custom table names (so User.MyUsers instead of dbo.AspNetUsers): " The entity types 'IdentityUser' and 'ApplicationUser' cannot share table 'MyUsers' because they are not in the same type hierarchy or do not have a valid one to one foreign key relationship

问题 I have an ASP.NET MVC 3 app that is using SQL Server CE 4.0 and Entity Framework 4.1 Code First. It works fine locally , but in production, it fails with the following error: The model backing the 'foobar' context has changed since the database was created. Either manually delete/update the database, or call Database.SetInitializer with an IDatabaseInitializer instance. For example, the DropCreateDatabaseIfModelChanges strategy will automatically delete and recreate the database, and

问题 EF4.1-Code-First-Gurus! I wonder if there is a more elegant way to handle the following ASP.NET MVC 3 EF 4.1 Code First scenario: Lets say we have the following POCOs: public class Entity { [Key] public int Id { get; set; } [ScaffoldColumn(false)] public DateTime CreatedOn { get; set; } [ScaffoldColumn(false)] public DateTime ModifiedOn { get; set; } } and public class Person : Entity { public string FirstName { get; set; } public string LastName { get; set; } public DateTime Birthday { get;

问题 What is the minimal permission needed on a sql server user/login for it to be able to run entity framework code first database migrations? I naively would have thought that a user with the roles db_datareader, db_datawriter, Grant Alter on the Schema and Grant Create Table would be permissive enough. 回答1: you need following permision on the database. [db_datareader] [db_datawriter] [db_ddladmin] For full control over database use [db_owner] 回答2: Clearly it depends on what your migrations are/