The 1-0..1 relation in your database is directly visible. It is built between Course and OnlineCourse tables where Course is principal in relation (1) and OnlineCourse is dependent with FK configured on CourseID. FK is also PK of the OnlineCourse = it must be unique and because of that it is 0..1. Database “always” uses … Read more
While you are in debug mode within the catch {…} block open up the “QuickWatch” window (ctrl+alt+q) and paste in there: ((System.Data.Entity.Validation.DbEntityValidationException)ex).EntityValidationErrors This will allow you to drill down into the ValidationErrors tree. It’s the easiest way I’ve found to get instant insight into these errors. For Visual 2012+ users who care only about the … Read more
Use SQL Compact 4.0 (download both SqlCE and tools by web platform installer) – EF Code first has direct support for that. The only difference will be that your application will use connection string to big SQL Server: <add name=”MyDbContext” provider=”System.Data.SqlClient” connectionString= “Data Source=…;InitialCatalog=…;Integrated Security=SSPI” /> and your tests will use connection string to SQL … Read more
This is not the way you are supposed to use DbContext, and because of that it is almost impossible to reload the data. Keeping a single context around for a long time is incorrect usage. The link will also answer why your tracked entities are not updated. You can selectively reload a single entity by … Read more
Remove your Essence2EssenceSet model class. If junction table contains only keys of related entities participating in many-to-many relations it is not needed to map it as entity. Also make sure that your fluent mapping of many-to-many relations specifies schema for table: mb.Entity<Essence>() .HasMany(e => e.EssenceSets) .WithMany(set => set.Essences) .Map(mc => { mc.ToTable(“Essence2EssenceSet”, “Com”); mc.MapLeftKey(“EssenceID”); mc.MapRightKey(“EssenceSetID”); … Read more
EF seems to use INNER JOIN for including a required and LEFT OUTER JOIN for including an optional navigation property. Example: public class Order { public int Id { get; set; } public string Details { get; set; } public Customer Customer { get; set; } } public class Customer { public int Id { … Read more
It is not possible. Relations in EF follows exactly same rules as in the database. It means that principal table must have unique identifier which is referenced by dependent table. In case of database the identifier can be either primary key or unique column(s) of principal table. Otherwise it is not valid relation. Entity framework … Read more
This is wrong connection string. Once you are using model-first / database-first (EDMX) you must use Entity connection string with referencing .ssdl, .msl and .csdl metadata files. Also be aware that you must create your database in design time when creating model from EDMX = you must generate SQL script and execute it to create … Read more
Both these approaches should work: public class Product { public int ProductId { get; set; } public string Name { get; set; } [ForeignKey(“Category”)] public string CId { get; set; } public virtual Category Category { get; set; } } Or: public class Product { public int ProductId { get; set; } public string Name … Read more
SetValues never updates navigation properties. When you execute your code it only knows about changes in simple / complex properties of the entity passed to your Update method. EF even don’t know about related entities of the entity passed to your Update method. You must manually tell EF about each change in your object graph … Read more