ef-code-first

问题 This code has worked for me before but i am not sure anymore what has been causing this error. My only guess is that when i try to create a Player, the Team Data is being sent back to Team table and its trying to duplicate but since TeamId is unique hence this error. Error The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.Players_dbo.Teams_TeamId". The conflict occurred in database "Web", table "dbo.Teams", column 'TeamId'. The statement has been terminated. Player

问题 This code has worked for me before but i am not sure anymore what has been causing this error. My only guess is that when i try to create a Player, the Team Data is being sent back to Team table and its trying to duplicate but since TeamId is unique hence this error. Error The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.Players_dbo.Teams_TeamId". The conflict occurred in database "Web", table "dbo.Teams", column 'TeamId'. The statement has been terminated. Player

问题 I have two tables a parent and a child table. The child table has a column sortorder (a numeric value). Because of the missing support of the EF to persist a IList inclusive the sort order without exposing the sortorder (see: Entity Framework persisting child collection sort order) my child class has also a property SortOrder, so that i can store the children with the sort order. In contrast to the autor of the referenced question i try to load the children always sorted. So if i load a

问题 I have two tables a parent and a child table. The child table has a column sortorder (a numeric value). Because of the missing support of the EF to persist a IList inclusive the sort order without exposing the sortorder (see: Entity Framework persisting child collection sort order) my child class has also a property SortOrder, so that i can store the children with the sort order. In contrast to the autor of the referenced question i try to load the children always sorted. So if i load a

问题 I have a 1-to-0..1 relationship defined in an Entity Framework code first model like this: public class Album { public int AlbumId { get; set; } public int StampId { get; set; } public Stamp Stamp { get; set; } // other properties } public class Stamp { public int StampId { get; set; } public int AlbumId { get; set; } [Required] public Album Album { get; set; } // other properties } So.. an album has 0..1 stamps, a stamp always has exactly one album. The configuration I have here works nicely

问题 Ok, I have been pulling out my hair because I simply cannot make a many to many relationship. I have the following two models: public class UserProfile { [Key] [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)] public int UserId { get; set; } public string UserName { get; set; } public string CompanyName { get; set; } public string FirstName { get; set; } public string Lastname { get; set; } public string EmailAddress { get; set; } public string PhoneNumber { get; set; } public

问题 Ok, I have been pulling out my hair because I simply cannot make a many to many relationship. I have the following two models: public class UserProfile { [Key] [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)] public int UserId { get; set; } public string UserName { get; set; } public string CompanyName { get; set; } public string FirstName { get; set; } public string Lastname { get; set; } public string EmailAddress { get; set; } public string PhoneNumber { get; set; } public

问题 In my MVC application, I have an entity relation between Student and Lookup tables with StatusID-LookupKey and GenderID-LookupKey pairs inestead of (StatusID-ID and GenderID-ID pairs). However, not being able to define the LookupKey column as the matching parameter with the StatusID and GenderID, I have to use ID column of Lookup table. How can I use InverseProperty and match the related columns to the LookupKey column? Thanks in advance. Here are the Lookup table and the entities below:

问题 I am having below mentioned 2 models. GeoLocation Model : public class GeoLocation { public GeoLocation() { } public int Id { get; set; } public double Latitude { get; set; } public double Longitude { get; set; } } Provider Model : public class Provider { public Provider() { Id = Guid.NewGuid(); Created = DateTime.Now; } public Guid Id { get; set; } [Required] public string Name { get; set; } public virtual GeoLocation Location { get; set; } } Repository method : public void SetLocation

问题 i am trying to use EF Tracing utility with EF 5.0 (code first). but this works only object context which requires edmx file. http://code.msdn.microsoft.com/EFProviderWrappers anybody is having workaround for EF code first with DBContext? anand 回答1: From the Q&A section of the site, the author has this code for using Code First: Use the DbCommand constructor overload in your DbContext... var context = new NorthwindContext(CreateConnectionWrapper(@"name=NorthwindContext")); And the