[英]Problems creating a Foreign-Key relationship on Entity Framework
i'm having trouble configuring a foreign key relationship in my Entity Framework fluent Api: 我在我的Entity Framework流畅的Api中配置外键关系时遇到问题:
Here is the head of the report: 以下是报告的负责人:
public class Testata
{
public Testata() { Details = new List<Dettaglio>(); }
public virtual int IDTEST { get; set; }
public virtual string Value { get; set; }
public virtual int IDDETAIL { get; set; }
public virtual string IDTESTALT { get; set; }
public virtual byte[] BLOB { get; set; }
public virtual IList<Dettaglio> Details { get; set; }
}
This is the report's detail 这是报告的细节
public class Dettaglio
{
public virtual int IDDETAIL { get; set; }
public virtual int IDTEST { get; set; }
public virtual string DSDETAIL { get; set; }
public virtual Testata TEST_TABLE { get; set; }
}
And this is my fluent API definition of both. 这是我对两者的流畅API定义。 Head of the report:
报告负责人:
public TEST_TABLEMap()
{
// Primary Key
this.HasKey(t => t.IDTEST)
.Property(t => t.IDTEST)
.IsRequired()
.HasColumnType("Int")
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
.HasColumnName("IDTEST");
// Table & Column Mappings
this.ToTable("TEST_TABLE");
this.Property(t => t.Value).HasColumnName("DSVALUETEST");
this.Property(t => t.IDTESTALT).HasColumnName("IDTESTALT");
this.Property(t => t.BLOB).HasColumnName("BLOB");
}
Detail of the report: 报告详情:
public TEST_DETAILMap()
{
// Primary Key
this.HasKey(t => t.DSDETAIL);
// Properties
this.Property(t => t.DSDETAIL);
// Table & Column Mappings
this.ToTable("TEST_DETAIL");
this.Property(t => t.IDDETAIL).HasColumnName("IDDETAIL");
// this.Property(t => t.IDTEST).HasColumnName("IDTEST");
this.Property(t => t.DSDETAIL).HasColumnName("DSDETAIL");
// Relationships
this.HasOptional(t => t.TEST_TABLE)
.WithMany(t => t.Details)
.HasForeignKey(d => d.IDDETAIL).WillCascadeOnDelete(true);
}
On execution i always get this error 在执行时我总是得到这个错误
System.Data.Entity.Edm.EdmAssociationType: : Multiplicity conflicts with the referential constraint in Role 'Dettaglio_TEST_TABLE_Target' in relationship 'Dettaglio_TEST_TABLE'.
System.Data.Entity.Edm.EdmAssociationType :: Multiplicity与关系'Dettaglio_TEST_TABLE'中Role'Dettaglio_TEST_TABLE_Target'中的引用约束冲突。 Because all of the properties in the Dependent Role are non-nullable, multiplicity of the Principal Role must be '1'.
由于“从属角色”中的所有属性都是不可为空的,因此“主体角色”的多重性必须为“1”。
Which, i guess, means i'm failing something at foreign key definition, but i don't really know where to look at. 我猜,这意味着我在外键定义方面失败了,但我真的不知道在哪里看。 Any help/hint is much appreciated.
非常感谢任何帮助/提示。
There is a conflict between your foreign key property in class Dettaglio
... 您在
Dettaglio
课程中的外键属性之间存在冲突......
public virtual int IDTEST { get; set; }
...which has a non-nullable type ( int
) and therefore cannot be optional and your mapping... ...具有非可空类型(
int
),因此不能是可选的,你的映射......
this.HasOptional(t => t.TEST_TABLE) //...
...where you want the relationship to be optional. ...你希望这种关系是可选的。
If you indeed want an optional relationship use a nullable FK property: 如果您确实需要可选关系,请使用可空的FK属性:
public virtual int? IDTEST { get; set; }
Otherwise you must use HasRequired
for a required relationship with a non-nullable FK property. 否则,您必须使用
HasRequired
获取与不可为空的FK属性的必需关系。
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