I have ignored a column through fluent API but want to populate that property while executing stored procedure using some logic. But it is not mapping the ignored column property. Please let me know if there is any way to do this in Entity framework code first.
I've faced with the same problem recently. The only solution I found is a class hierarchy:
public class MyEntityBase {
public int Id { get; set; }
}
public class MyEntity: MyEntityBase {
...
}//This class is mapped to DB with a fluent API and does not contain ignored property.
//Also it does not have derivative classes, so EF will not create class inheritance in DB.
public class DerivedEntity: MyEntityBase {
public int IgnoredProperty { get; set; }
}//Use this class while executing stored procedures
P.S. Do not mark class MyEntityBase as ABSTRACT - EF will map this relationship as database inheritance.
Related
I am using the SQLite.Net-PCL library to manage the SQLite database in my UWP app. The documentation says that calling CreateTableAsync is able to add columns to the table if a properly is added to the data model. However, when I add a property, the application throws an exception that says the table does not have a column named . This means that the new column was not created automatically. I am calling CreateTableAsync in the constructor of the class that manages database calls for the table with a repository design pattern.
I think you missed decorations [PrimaryKey, AutoIncrement] for your class model. Please check the following DataTemple class.
public class DataTemple
{
[PrimaryKey, AutoIncrement]
public int Id { get; set; } //primary key
public string Name { get; set; }
public string Age { get; set; }
}
For more detail you could also refer this sample.
I pulled out all of my CreateTableAsync calls from the repository class constructors and moved them into separate Init Tasks so I can properly await. Now I can add columns to any table without problems.
I want to implement an interface defined in Dev Express IResource in my EF Code First business object.
public class JResource : IResource , IXafEntityObject
{
[Key]
public int IdKey { get; set; }
[NotMapped]
public object Id => IdKey; // since IResource wants this.
// other properties
}
When I run my application to create the database I get an error that I need to define the key for this EntityType.
I think the problem is that EF wants to regard Id as the Key but I have made Id NotMapped since I want it to be an Int and the interface wants it to be an object.
Is there a work around?
It turned out that I was using the wrong reference for the [Key] attribute.
The correct one is
System.ComponentModel.DataAnnotations.KeyAttribute
I am using MVC4 with EF5 database first and Newtonsoft.Json for serializing objects to JSON for example in Web API controllers.
To avoid the problem of self referencing loops i set the attribute [JsonIgnore] to the specific collections in my generated classes.
My problem is now that each time i update my model i have to readd the attributes to the classes.
How can i avoid that? I think i have to edit the DBModel.tt script? What have i to do?
You should be able to use a metadata class with the MetadataType attribute. If your generated class is:
public partial class MyClass{
public string SomeProperty {get; set; }
public string SomePropertyToIgnore {get; set; }
}
Then you need to create a metadata class like so (in the same namespace):
public class MyClass_Metadata{
[JsonIgnore]
public string SomePropertyToIgnore {get; set; }
}
The create a partial of your generated class (in the same namespace) with the MetadatType attribute applied:
[MetadataType(typeof(MyClass_Metadata))]
public partial class MyClass{
}
Ref: http://msdn.microsoft.com/en-us/library/ee707339(v=vs.91).aspx
I regularly have the following structure:
MyClass
public virtual ICollection<Version> Versions { get; set; }
public virtual Version CurrentVersion { get; set; }
That is, there is a list of stuff, and some class both points to that list, and one specific item in that list - either the current version of many versions, the next upcoming event in a list of events, etc.
In my schema what I'd like to end up with is a Foreign Key pointing from Version to MyClass - that much works out properly. But then I'd like a Foreign Key pointing from MyClass to Version representing the CurrentVersion property, with no Foreign Key pointing back - I don't want the extra storage or bother of telling a Version what MyClass it's the CurrentVersion for, if any. Put another way, I'd like this second relationship to be one-way from MyClass to Version, even though it's one-to-one.
What EF Code First gives me instead is the normal one-to-many on the first property, with the FK from Version to MyClass, but then a full one-to-one relationship on the second property with an FK pointing in both directions - so the underlying schema for Version ends up with MyClass_Id and MyClass_Id1.
So, is there a way to get a one-way relationship in EF Code First without resorting to the Fluent API? It looked like maybe System.ComponentModel.DataAnnotations.Schema.InverseProperty had a shot at it, but it didn't seem to offer a way to say "Don't generate one."
The key is to specify the InverseProperty on the property that points back, so that EF realizes it's to the Many-to-Many, not to the One-to-One.
public class MyClass
{
public int Id { get; set; }
public Version CurrentVersion { get; set; }
public ICollection<Version> Versions { get; set; }
}
public class Version
{
public int Id { get; set; }
[InverseProperty("Versions")]
public Versioned Versioned { get; set; }
}
I have custom entity (not from entity model), which have a property, wich return collection of EF entities (from entity model):
[DataContract]
public class MyEntity
{
[DataMember]
public List<Role> Roles { get; set; }
}
The 'Role' and 'RolePermission' entities are generated by EF4 from DB.
RolePermission has FOREGIN_KEY to Role, and EF4 was generated association between Role and RolePermission:
Role.RolePermissions --navigate property
RolePermission.Role --navigate property
Also, I have DomainService:
[EnableClientAccess()]
public class MyEntityService : DomainService
{
public List<MyEntity> GetMyEntities()
{
...
myEntityInstance.Roles = <GetRoles>
...
return <collection of MyEntities with Roles>
}
}
When I try to compile this, I get error:
Entity 'UserManager.Web.RolePermission' has a property 'RoleReference' with an unsupported type
When I put [Include] attribute to MyEntity.Roles property, I get the same error and this error:
Property 'Roles' of complex type 'MyEntity' is invalid. Complex types cannot have include members.
when I removed reference from RolePermission to Role (RolePermission.Role navigate property) by hands (from entity model), I get only this error in compile time:
The Entity 'Role' in DomainService 'RolesService' does not have a key defined. Entity types exposed by DomainService operations must have at least one public property marked with the KeyAttribute.
How can I resolve this situation? How can I return my custom object (MyEntity) with filled Roles property from MyEntityService?
A added [key] attr to Role.Metadata, and compile succesfull. But there are no MyEntity.Roles property on the client.
RIA services requires all objects passed back and forth between client to server to have a unique key so it knows which specific object you are modifying.
If you must have your own object as a wrapper for EF objects, just add an id member marked with [key] and maintain that value yourself.
[DataContract]
public class MyEntity
{
[key]
public int Id { get; set; }
[DataMember]
public List<Role> Roles { get; set; }
}
There seems to be something wrong with the design if you need to do that. What is the parent of a group of roles in your application? Why not just query roles?