Implementing Zero Or One to Zero Or One relationship in EF Code first by Fluent API
c# ef-code-first entity-framework entity-relationship fluent
Question
I have two POCO classes
public class Order
{
int id;
string code;
int? quotationId; //it is foreign key
public int Id{get;set;}
public string Code{get;set;}
public int? QuotationId{get;set;}
Quotation quotation;
public virtual Quotation Quotation { get; set; }
....
}
public class Quotation
{
int Id;
string Code;
public int Id{get;set;}
public string Code{get;set;}
Order order;
public virtual Order Order { get; set; }
....
}
each Order may made from one or zero quotation, and each quotation may cause an order, so I have an "one or zero" to "one or zero" relation, how can I implement this, in EF Code first by fluent API?
Accepted Answer
By changing pocos to:
public class Order
{
public int OrderId { get; set; }
public virtual Quotation Quotation { get; set; }
}
public class Quotation
{
public int QuotationId { get; set; }
public virtual Order Order { get; set; }
}
and using these mapping files:
public class OrderMap : EntityTypeConfiguration<Order>
{
public OrderMap()
{
this.HasOptional(x => x.Quotation)
.WithOptionalPrincipal()
.Map(x => x.MapKey("OrderId"));
}
}
public class QuotationMap : EntityTypeConfiguration<Quotation>
{
public QuotationMap()
{
this.HasOptional(x => x.Order)
.WithOptionalPrincipal()
.Map(x => x.MapKey("QuotationId"));
}
}
we will have this DB(that means 0..1-0..1):
with special thanks to (Mr. Vahid Nasiri)
Popular Answer
@Masoud's procedure was:
modelBuilder.Entity<Order>()
.HasOptional(o => o.Quotation)
.WithOptionalPrincipal()
.Map(o => o.MapKey("OrderId"));
modelBuilder.Entity<Quotation>()
.HasOptional(o => o.Order)
.WithOptionalPrincipal()
.Map(o => o.MapKey("QuotationId"));
It gives:
By changing the code to:
modelBuilder.Entity<Order>()
.HasOptional(o => o.Quotation)
.WithOptionalPrincipal(o=> o.Order);
It gives:
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