I'm new to EF and am having issues trying to create a unidirectional navigation association (0 to many) using the Fluent API. Here are simplified versions of the classes:
public partial class Company
{
public int Id { get; set; }
// "Company" is NOT REQUIRED to have any BillingInfo records/objects
public virtual IList<BillingInfo> BillingInfos { get; set; }
}
public partial class BillingInfo
{
public int Id { get; set; }
// A "BillingInfo" requires ONE "Company"
public int Company_Id { get; set; }
}
I'm using EF 6.1 Code First with migrations enabled along with SQL Server 2012.
In my derived EntityTypeConfiguration classes for "Company" and "BillingInfo", I've tried every which way I can think of to achieve:
A Company DOES NOT REQUIRE any BillingInfo records, but MAY HAVE MANY.
A BillingInfo DOES REQUIRE only ONE Company.
Maintain a unidirectional navigation between Company and BillingInfo. (don't want to have a Company navigation property on BillingInfo)
EF Migration creates the NON-NULLABLE Company_Id field in database, WITH a defined ForeignKey constraint.
All the methods I've tried, only gets me partially there. The closest I've come is this (but the only thing missing is the foreignkey constraint isn't created):
class CompanyConfig : EntityTypeConfiguration<Company>
{
public CompanyConfig()
{
this.HasOptional(company => company.BillingInfos)
.WithMany()
.Map(m => m.MapKey("Company_Id"));
}
}
Any ideas???
I think you should use the following code:
private class CompanyMapping : EntityTypeConfiguration<Company>
{
public CompanyMapping()
{
this.HasMany(o => o.BillingInfos).WithOptional().HasForeignKey(fk => fk.Company_Id);
}
}
private class BillingInfoMapping : EntityTypeConfiguration<BillingInfo>
{
public BillingInfoMapping()
{
this.HasOptional(o => o.Company).WithMany(c=>c.BillingInfos).HasForeignKey(fk => fk.Company_Id);
}
}
Related
I have the following Entity class definition:
[Table("Users")]
public class WebUser
{
public virtual int Id { get; set; }
public virtual ICollection<Client> Clients { get; set; }
// more properties...
}
Notice that table name is different than the class name. I also have a ClientUsers table which is a many-to-many mapping for clients and users. Problem is, when I try to access the webUser.Clients property I get the following exception:
"Invalid object name 'dbo.ClientWebUsers'."
Looks like Entity Framework is trying to guess the name of the third table, but it apparently was not smart enough to take into account the table attribute that I have there. How can I tell EF that it is ClientUsers and not ClientWebUsers? Also what rule does it follow to know which table name comes first and which one comes second in the new table name? I think it's not alphabetical order.
I'm using EF 5.0. Thanks!
From the looks of things you're using Code First, so I'll answer accordingly. If this is incorrect, please let me know.
I believe the convention being used to determine the name of the many-to-many table is determined by the order in which they occur as DbSet properties in your SomeContext : DbContext class.
As for forcing EntityFramework to name your table whatever you like, you can use the Fluent API in the OnModelCreating method of your SomeContext : DbContext class as follows:
public class DatabaseContext : DbContext
{
public DatabaseContext()
: base("SomeDB")
{
}
public DbSet<WebUser> Users { get; set; }
public DbSet<Client> Clients { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<WebUser>().HasMany(c => c.Clients)
.WithMany(p => p.WebUsers).Map(
m =>
{
m.MapLeftKey("ClientId");
m.MapRightKey("UserId");
m.ToTable("ClientUsers");
});
}
}
This assumes your classes are something like the following:
[Table("Users")]
public class WebUser
{
public virtual int Id { get; set; }
public virtual ICollection<Client> Clients { get; set; }
// more properties...
}
public class Client
{
public int Id { get; set; }
public ICollection<WebUser> WebUsers { get; set; }
// more properties
}
Finally, here's an integration test (NUnit) demonstrating the functionality working. You may need to drop your database before running it as Code First should want to update/migrate/recreate it.
[TestFixture]
public class Test
{
[Test]
public void UseDB()
{
var db = new DatabaseContext();
db.Users.Add(new WebUser { Clients = new List<Client> { new Client() } });
db.SaveChanges();
var webUser = db.Users.First();
var client = webUser.Clients.FirstOrDefault();
Assert.NotNull(client);
}
}
Edit: Link to relevant documentation for the Fluent API
Rowan's answer (adding here for reference):
Here is the information on how to configure a many-to-many table (including specifying the table name). The code you are after is something like:
modelBuilder.Entity<WebUser>()
.HasMany(u => u.Clients)
.WithMany(c => c.WebUsers)
.Map(m => m.ToTable("ClientUsers");
~Rowan
I've posted my problem on codeplex http://entityframework.codeplex.com/workitem/2087.
There are also some questions posted here but they are not successfully answered.
See
Mapping TPT in EF Code First 4.1 w/ Different Primary Keys
Entity Framework 4 - TPT Inheritance in Features CTP5 (code first): rename foreign key column on inherited table
How can I use TPT inheritance models when primary keys have different names?
Is it now possible to have different column names for the primary keys when using TPT?
May be with 6.1.0
In TPT you're essentially do not want to declare the key in the subclasses, you'd miss the point otherwise.
If you must have a different Id name, just make proxy properties in the subclasses mapping to the base Id one.
public class BaseEntity
{
public int Id { get; set; }
}
public abstract class SubEntity : BaseEntity
{
public BaseId
{
get => Id;
set => Id = value;
}
}
Consider marking the sub fields as NotMapped, which in case you shouldn't include them in your LINQ queries.
With EF 6.4 I was able to use the ColumnAttribute to rename the Primary Key column in the dependent class
[Table("Person")]
public class Person
{
[Key]
public virtual int PersonId { get; set; }
// Person atributes...
}
[Table("Employee")]
public class Employee : Person
{
[Column("EmployeeId")] // <- Name of the primary Key column in the Database
public override int PersonId { get; set }
// Employee Attributes
}
Look at this code snip. Its work correct for me:
public partial class Person
{
// Any other PK name can thrown an exception
public int ID { get; set; }
}
public partial class Employee : Person
{
// Hide base class ID
private new int ID { get; set }
// Define derived class ID (that wrapped inherited ID)
[NotMapped]
public int EmployeeID
{
get { return base.PersonID; }
set { base.PersonID = value; }
}
}
Now, we must rename the inherited ID (with fluent API) for database table:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Employee>()
.Property(e => e.ID)
.HasColumnName("EmployeeID");
}
this may seem very easy to solve, but the complication I'm having is that I have a table per hierarchy to store all of the entities and I'm not able to create the relationships over the same table. Here is what I have in the DB and classes:
I have just one table named BaseObject with an ID, name and type. I will create two classes for those entities stored in there. Master and Component. The type column is the discriminator. I have another table to store the relationships between both: A master can have many components and a component also can have many other components.
This is the code I have for the classes:
public partial class BaseObject
{
public BaseObject()
{
}
public System.Guid ID { get; set; }
public string Name { get; set; }
public Nullable<int> Type { get; set; }
}
public class MasterObject : BaseObject
{
public virtual ICollection<ComponentObject> Components { get; set; }
public MasterObject()
{
this.Components = new List<ComponentObject>();
}
}
public class ComponentObject : BaseObject
{
public virtual ICollection<MasterObject> MasterObjects { get; set; }
public ComponentObject()
{
this.MasterObjects = new List<MasterObject>();
}
}
And these are the mappings:
public class BaseObjectMap : EntityTypeConfiguration<BaseObject>
{
public BaseObjectMap()
{
// Primary Key
this.HasKey(t => t.ID);
// Table & Column Mappings
this.ToTable("BaseObject");
this.Property(t => t.ID).HasColumnName("ID");
this.Property(t => t.Name).HasColumnName("Name");
//configure the inheritance in here
this.Map<MasterObject>(m => m.Requires("Type").HasValue(1));
this.Map<ComponentObject>(m => m.Requires("Type").HasValue(2));
}
}
public class MasterObjectMap : EntityTypeConfiguration<MasterObject>
{
public MasterObjectMap()
{
this.HasMany<ComponentObject>(t => t.Components)
.WithMany(t => t.MasterObjects)
.Map(c =>
{
c.ToTable("ObjectComponents");
c.MapLeftKey("ComponentObjectID");
c.MapRightKey("BaseObjectID");
});
}
}
public class ComponentObjectMap : EntityTypeConfiguration<ComponentObject>
{
public ComponentObjectMap()
{
this.HasMany<MasterObject>(t => t.MasterObjects)
.WithMany(t => t.Components)
.Map(m =>
{
m.ToTable("ObjectComponents");
m.MapLeftKey("BaseObjectID");
m.MapRightKey("ComponentObjectID");
});
}
}
The thing is that when quering the DB, I can get a Master by accessing the DBSet Masters, but the Component collection always gives a non-sense exception saying that "Problem in mapping fragments starting at line 6:Condition member 'BaseObject.Type' with a condition other than 'IsNull=False' is mapped. Either remove the condition on BaseObject.Type or remove it from the mapping."
I don't understand what's happening. Of course if the classes where pointing each to a table, this would be very easy, but I suspect that is the root of my problem.
Also, I'm just starting with EF. I wanted to create the classes based on my existing DB that I wouldn't like to modify at all. Unless it's really needed. Please guide me if what I'm trying to do is right or wrong, or what should I do first to fully implement EF on this project that is currently using NHibernate.
Any help here? Thanks
Finally I found the issue thanks to this answer: EF4.1 Exception creating Database with table-per-hierarchy inheritance
The problem is in the mapping of the Base class. When using a base class and a discriminator to get the children classes, the discriminator MUST NOT BE a property in neither instance. Just removed the discriminator as property and it worked fine. In my example, column 'Type' is the discriminator.
Hope this helps to someone else.
I have an abstract base class for a few entities I'm defining. One of those derived entities is actually a non-abstract base class to another entity.
Following this code:
public abstract class BaseReportEntry {
public int ReportEntryId { get; set;}
public int ReportBundleId { get; set; } //FK
public virtual ReportBundle ReportBunde { get; set; }
}
//A few different simple pocos like this one
public PerformanceReportEntry : BaseReportEntry {
public int PerformanceAbsolute { get; set; }
public double PerformanceRelative { get; set; }
}
//And one with a second level of inheritance
public ByPeriodPerformanceReportEntry : PerformanceReportEntry {
public string Period { get; set; }
}
I'm using a base EntityTypeConfiguration:
public class BaseReportEntryMap<TReportEntry> : EntityTypeConfiguration<TReportEntry>
where TReportEntry : BaseReportEntry
{
public BaseReportEntryMap()
{
this.HasKey(e => e.ReportEntryId);
this.HasRequired(e => e.ReportsBundle)
.WithMany()
.HasForeignKey(e => e.ReportsBundleId);
}
}
Presumably this works fine for the one-level of inheritance but throw the following error for that one case where it has a second level:
The foreign key component 'ReportsBundleId' is not a declared property on type 'ByPeriodPerformanceReportEntry'
public class ByPeriodPerformanceReportEntryMap : BaseReportEntryMap<ByPeriodPerformanceReportEntry>
{
public ByPeriodPerformanceReportEntryMap ()
: base()
{
this.Property(e => e.Period).IsRequired();
this.Map(m =>
{
m.MapInheritedProperties();
m.ToTable("ByPeriodPerformanceReportEntries");
});
}
}
Here's ReportBundle class if needed
public class ReportsBundle
{
public int ReportsBundleId { get; set; }
public virtual ICollection<PerformanceReportEntry> PerformanceReportEntries{ get; set; }
public virtual ICollection<ByPeriodPerformanceReportEntry> ByPeriodPerformanceReportEntries{ get; set; }
}
The problem is not so much the second level of inheritance but that PerformanceReportEntry (the base of ByPeriodPerformanceReportEntry) is an entity while BaseReportEntry (the base of PerformanceReportEntry) is not.
Your mapping would work if PerformanceReportEntry would not be an entity - i.e. its mapping is not added to the model builder configuration and you have no DbSet for this type and it would not occur in a navigation collection in ReportsBundle.
Deriving the configuration from BaseReportEntryMap<ByPeriodPerformanceReportEntry> is not possible in this case - and it is not necessary because the mapping for the base properties already happened by the BaseReportEntryMap<PerformanceReportEntry>. Therefore you can use
public class ByPeriodPerformanceReportEntryMap
: EntityTypeConfiguration<ByPeriodPerformanceReportEntry>
But I have doubt that the resulting model is as you would expect it. I don't know what the PerformanceReportEntries and ByPeriodPerformanceReportEntries collections in ReportsBundle are supposed to express. Do you expect that ByPeriodPerformanceReportEntries is a collection filtered by the subtype? Do you expect that PerformanceReportEntries contains only the ReportsEntries that are PerformanceReportEntrys but not ByPeriodPerformanceReportEntrys? Do you expect that PerformanceReportEntries contains all entries including the ByPeriodPerformanceReportEntries?
Anyway, BaseReportEntry.ReportBundle is a navigation property mapped in PerformanceReportEntry (not in ByPeriodPerformanceReportEntry). That means that the inverse navigation property in class ReportsBundle must refer to PerformanceReportEntry which is the PerformanceReportEntries navigation collection. ByPeriodPerformanceReportEntries will introduce a second one-to-many relationship between ReportsBundle and ByPeriodPerformanceReportEntry (without a navigation property in ByPeriodPerformanceReportEntry). The inverse navigation property of ByPeriodPerformanceReportEntries will NOT be BaseReportEntry.ReportBundle.
My feeling is that you should not have the ReportsBundle.ByPeriodPerformanceReportEntries collection, but I am not sure what you want to achieve exactly.
Edit
Refering to your comment that you only have these two Report types your mapping is way too complicated in my opinion. I would do the following:
Remove the BaseReportEntry class and move its properties into PerformanceReportEntry. It makes no sense to have a base class that only one single other class derives from.
Remove the ByPeriodPerformanceReportEntries from ReportsBundle, so that ReportsBundle will be:
public class ReportsBundle
{
public int ReportsBundleId { get; set; }
public virtual ICollection<PerformanceReportEntry>
PerformanceReportEntries { get; set; }
}
Remove the BaseReportEntryMap and move the mapping into PerformanceReportEntryMap. Derive this map from EntityTypeConfiguration<PerformanceReportEntry>.
Correct the mapping. Currently it is wrong because you don't specify the inverse navigation property in WithMany. PerformanceReportEntryMap should look like this:
public class PerformanceReportEntryMap
: EntityTypeConfiguration<PerformanceReportEntry>
{
public PerformanceReportEntryMap()
{
this.HasKey(e => e.ReportEntryId);
this.HasRequired(e => e.ReportsBundle)
.WithMany(b => b.PerformanceReportEntries)
.HasForeignKey(e => e.ReportsBundleId);
}
}
Derive ByPeriodPerformanceReportEntryMap from EntityTypeConfiguration<ByPeriodPerformanceReportEntry> and specify only mappings for properties that are declared in ByPeriodPerformanceReportEntry, not again for the base properties. That already happened in PerformanceReportEntryMap. You don't need and can't specify it again because it will cause exactly the exception you had.
Use Table-Per-Hierarchy (TPH) inheritance instead of Table-Per-Concrete-Type (TPC), especially if you only have a few properties declared in ByPeriodPerformanceReportEntry. TPC is more difficult to use because it has problems with database-generated identities and with polymorphic associations (which you have in your relationship between PerformanceReportEntry and ReportsBundle). The problems are explained in more details here. TPH instead offers the best performance. ByPeriodPerformanceReportEntryMap would then look like this:
public class ByPeriodPerformanceReportEntryMap
: EntityTypeConfiguration<ByPeriodPerformanceReportEntry>
{
public ByPeriodPerformanceReportEntryMap()
{
this.Property(e => e.Period).IsRequired();
}
}
No explicit configuration for TPH is necessary because it is the default inheritance mapping.
I'm trying to use the Entity Framework CTP5 Fluent API to map an exist database. I have the following classes:
public class Shop
{
public long Id
{
get;
set;
}
}
public class Sale
{
public long Id
{
get;
set;
}
public virtual Shop Shop
{
get;
set;
}
}
The corresponding tables are called "Stores" and "Sales". Sales has a StoreId foreign key that points to the Id field in the Stores table.
I'm struggling to map the Sale.Shop.Id to the StoreId in the table. I'm not at liberty to change it to ShopId, so need to map it.
In CTP4, I was using:
modelBuilder.Entity<Sale>().MapSingleType(x =>
new
{
Id = x.Id,
StoreId = x.Shop.Id
});
I tried the following:
modelBuilder.Entity<Sale>().Property(x => x.Shop.Id).HasColumnName("StoreId");
However, it seems this only works with a primitive type.
How do I specify this mapping?
Update: I've added a revised version for the Release Candidate of EF 4.1 below
After some hunting, I've found the answer that works for me:
EF4.1 RC version:
modelBuilder.Entity<Booking>().HasRequired(b => b.Booker)
.WithMany(m => m.BookedSlots).Map(p=>{
p.MapKey("BookerID");
});
in your case:
modelBuilder.Entity<Sale>().HasRequired(sale => sale.Shop)
.WithMany().Map(s=> {
s.MapKey("StoreId");
});
My version is slightly different because I have navigation properties on both sides of the relationship.
I think the best way to solve this would be to upgrade your independent Association to be a Foreign Key Association meaning that instead of hiding the foreign key ShopId, actually including it in Sale class. Then you can use Data Aannotations/Fluent API to change its column name to match to your existing schema:
public class Shop
{
public long Id { get;set; }
}
public class Sale
{
public long Id { get; set; }
[Column(Name="StoreID")]
public long ShopId { get; set; }
public virtual Shop Shop { get; set; }
}
Which results to the desired DB Schema:
I think what you're looking for is the RelatedTo attribute. More information in this ADO.NET team blog post.