public class Address
{
[Key]
public virtual string AddressId { get; set; }
public virtual Site Site { get; set; }
}
public class Site
{
[Key]
public virtual int SiteId { get; set; }
public virtual Address Address { get; set; }
}
public class SiteMappings : EntityTypeConfiguration<Site>
{
public SiteMappings()
{
HasRequired(s => s.Address)
.WithOptional(a => a.Site)
.Map(s => s.MapKey("AddressId"))
.WillCascadeOnDelete(false);
}
}
var addresses = new List<Address>
{
new Address { AddressId = "1" }
};
addresses.ForEach(s => context.Addresses.AddOrUpdate(p => p.AddressId, s));
var sites = new List<Site>
{
new Site { SiteId = 1, Address = addresses.Single(s => s.AddressId.Equals("1"))}
};
sites.ForEach(s => context.Sites.AddOrUpdate(p => p.SiteId, s));
Violation of PRIMARY KEY constraint 'PK_dbo.Addresses'. Cannot insert duplicate key in object 'dbo.Addresses'. The duplicate key value is (1)
看来是当我尝试添加新的“站点”时，也插入了新的“地址”。如何避免这种情况？我刚才添加了如何在DBcontext中插入现有的“地址”。我是Entity Framework的新手，非常感谢您的帮助。提前致谢！
通过插入当前上下文管理的“地址”，我能够解决此问题。
new Site { SiteId = 1, Address = context.Addresses.FirstOrDefault(a => a.AddressId.Equals("1"))}
下面的代码将利用由当前上下文管理的现有“地址”，而不是尝试插入新的“地址”。
context.Addresses.FirstOrDefault(a => a.AddressId.Equals("1"))}
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我来说两句