code-first

问题 I am learning Entity Framework with UWP. I tried dropping a table by deleting it from DbContext. When running the code after migration I received an error that dropping primary key is not supported with UWP. This article, https://docs.efproject.net/en/latest/providers/sqlite/limitations.html, recommends using sql(string) method. This article, https://msdn.microsoft.com/en-us/data/jj592907.aspx, has an example I am trying to follow. using (var context = new BloggingContext()) { var blogs =

问题 I need to create a many-to-many table relationship in which the elements of one table are shared by the elements of a second table. I've read the multitude of similar posts, but I'm clearly still wrong somewhere. I've reduced my problem to this simple example. I have two tables: Beverages and Ingredients. I want the Ingredients to be shared among the Beverages. Is the problem how I've created the bridge table? (Can I do without a bridge table?) Or is the problem in how I'm managing the data

问题 I have these classes: Class Parent { [Required] String Name ; Child child ; } Class Child { [Required] Child FirstName ; [Required] Child LastName ; } I have a form showing the Parent entity fields including the Childs's. With my configuration the child's FistName and LastName are required and if left blank causes validation to fail. What I need is have validation pass if both the child's FirstName and LastName are submitted blank. If either FirstName or LastName is submitted then the other

问题 My integration tests are use a live DB that's generated using the EF initalizers. When I run the tests individually they run as expected. However when I run them all at once, I get a lot of failed tests. I appear to have some overlapping going on. For example, I have two tests that use the same setup method. This setup method builds & populates the DB. Both tests perform the same test ACT which adds a handful of items to the DB (the same items), but what's unique is each test is looking for

问题 I am using Entity Framework 6.3 for an MVC 5 application, using code-first (for the first time) with SQL Server 2012. The Database does not exist before hand, it is all being created from scratch by EF. When I attempt to start the application, and hence EF should create the database, it's giving me the following SqlException error message: "There is already an object named 'TableName' in the database." I have in my project the following very basic Entity: [Table("TableName")] public class

问题 Following on from earlier posts today: Entity framework one to zero or one relationship without navigation property Understanding ForeignKey attribute in entity framework code first I'm now trying to configure the following relationships: Item1 has optional RawData Item2 has optional RawData Item3 has optional RawData RawData must be attached to either Item1, Item2 or Item3 - it would not be expected to exist on its own. Current structure is: class ItemX { [Key] public int Id { get; set; }

问题 Using Entity Framework CTP 5 I am trying to make a list of foreign keys in my class. But I keep getting an error which says RelatedTo can not be found. Here is the code: public class VertragsVerweis : GenericBLL { [Key] public String Uid { get; set; } public String VertagsVerweisNr { get; set; } public String Bezeichnung { get; set; } public Boolean Reparatur { get; set; } [RelatedTo(RelatedProperty="Artikel")] public List<Artikel> Artikelen { get; set; } } This gives me the error: Error 2

问题 I’m developing a MVC Website based in codeplex EFMVC solution, and I’m using Entity Framework and Repository, Unit of Work and Command Patterns. My website needs to be a SaaS solution (software as a service) multiple database. In my legacy Asp.Net WebForms I have a XML file that holds all the different string connections and I’m trying to use the same strategy. So in my LoginController I create a command that has company (to identify in which database will be connected) username and password.

问题 I have been supplied a DB, and I need to get Code First set up for it. I think I'm mostly done, the problem that I'm running into right now is I want to change some of the foreign key names in the entities to make a little more sense. Let's say I have two tables, Person and Location, that look like this: Person ------ PersonId int not null (PK) DefaultLocation int not null (FK) Location -------- LocationId int not null (PK) For the location entity, I think I've got it: public class Location {

问题 I am working on an asp.net MVC 3 web application and I am using database first, but after I have mapped the DB tables into entity classes using entity framework, I am interacting with these tables as I will be interacting on the code first approach by dealing with Database tables as classes an objects. So after mapping the tables into entity classes I find that the code first approach and DB first are very similar but except of start writing the entities classes from scratch (as in code first