實體框架 - 與外鍵刪除對象，並保留父

Question

我有以下型號：

public class Company 
{ 
    //Primary key 
    public string ID { get; set; } 

    //Foreign key 
    public int? LogotypeID { get; set; } 
} 

和

public class Logotype 
{ 
    //Primary key 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public int? ID { get; set; } 

    //Foreign key 
    public string CompanyID { get; set; } 
} 

如何從公司表中刪除標識，沒有刪除公司行？

使用：
http://msdn.microsoft.com/en-us/library/system.data.entity.dbset.remove(v=vs.113).aspx DbSet.Remove（打印商標）thows以下異常：

{"The DELETE statement conflicted with the REFERENCE constraint \"FK_dbo.Companies_dbo.Logotypes_LogotypeID\". The conflict occurred in database \"ShipReg\", table \"dbo.Companies\", column 'LogotypeID'.\r\nThe statement has been terminated."} 

任何想法？

BR， 添

Answer 1

在打印商標表中的公司加入虛擬財產一樣

public class Company 
{ 
    //Primary key 
    public string ID { get; set; } 

    //Foreign key 
    public int? LogotypeID { get; set; } 

    public virtual Logotype Logotype {get;set;} 
} 

然後

dbContext.Entry<Company>(company).State=EntityState.Modified; 
dbContext.Entry<Logotype>(company.Logotype).State=EntityState.Deleted;