我有一个实体DbDropPhoto,DbReferencePhoto和DbSimpleLine。 DbSimpleLine可以三种不同状态存储在数据库中:DropPhotoHorizontalLine,DropPhotoVerticalLine,DbReferencePhoto。这些状态中的每一个相互抵消。例如,作为DropPhotoVerticalLine的SimpleLine,会将DropPhotoHorizontalLine和DbReferencePhoto设置为null:
[Table("DropPhotos")]
public class DbDropPhoto
{
[Key]
public Guid DropPhotoId { get; set; }
public int ZDiameterInPixels { get; set; }
public virtual DbSimpleLine SimpleHorizontalLine { get; set; }
public virtual DbSimpleLine SimpleVerticalLine { get; set; }
}
public class DbReferencePhoto
{
[Key]
public Guid ReferencePhotoId { get; set; }
public virtual DbSimpleLine SimpleLine { get; set; }
}
[Table("SimpleLines")]
public class DbSimpleLine
{
[Key]
public Guid SimpleLineId { get; set; }
public virtual DbReferencePhoto ReferencePhoto { get; set; }
public virtual DbDropPhoto DropPhotoHorizontalLine { get; set; }
public virtual DbDropPhoto DropPhotoVerticalLine { get; set; }
}
我当前的配置:
modelBuilder.Entity<DbDropPhoto>()
.HasRequired(s => s.SimpleHorizontalLine)
.WithRequiredPrincipal(ad => ad.DropPhotoHorizontalLine);
modelBuilder.Entity<DbDropPhoto>()
.HasRequired(s => s.SimpleVerticalLine)
.WithRequiredPrincipal(ad => ad.DropPhotoVerticalLine);
modelBuilder.Entity<DbReferencePhoto>()
.HasRequired(s => s.SimpleLine)
.WithRequiredPrincipal(ad => ad.ReferencePhoto);
我正在尝试保存新的dbSimpleLine:
public async Task CreateOrUpdateSimpleLine(List<DbSimpleLine> dbSimpleLines)
{
using (var context = new DDropContext())
{
foreach (var dbSimpleLine in dbSimpleLines)
{
var dbSimpleLineToUpdate = await context.SimpleLines.FirstOrDefaultAsync(x => x.SimpleLineId == dbSimpleLine.SimpleLineId);
if (dbSimpleLineToUpdate != null)
{
try
{
context.Entry(dbSimpleLineToUpdate).CurrentValues.SetValues(dbSimpleLine);
}
catch (Exception e)
{
throw new Exception(e.Message);
}
}
else
{
context.SimpleLines.Add(dbSimpleLine);
}
}
await context.SaveChangesAsync();
}
}
当我这样做时,我会得到一个例外:
System.InvalidOperationException:'角色更改冲突 关系的“ DbDropPhoto_SimpleHorizontalLine_Target” 已检测到“ DDrop.Db.DbDropPhoto_SimpleHorizontalLine”。
答案 0 :(得分:2)
当您具有同一类的多个实例时,应显式定义外键。这意味着:
[Table("DropPhotos")]
public class DbDropPhoto
{
[Key]
public Guid DropPhotoId { get; set; }
public int ZDiameterInPixels { get; set; }
public int? SimpleHorizontalLineId { get; set; }
[ForeignKey("SimpleHorizontalLineId")]
public virtual DbSimpleLine SimpleHorizontalLine { get; set; }
public int? SimpleVerticalLineId { get; set; }
[ForeignKey("SimpleVerticalLineId")]
public virtual DbSimpleLine SimpleVerticalLine { get; set; }
}
public class DbReferencePhoto
{
[Key]
public Guid ReferencePhotoId { get; set; }
public Guid SimpleLineId { get; set; }
[ForeignKey("SimpleLineId")]
public virtual DbSimpleLine SimpleLine { get; set; }
}
[Table("SimpleLines")]
public class DbSimpleLine
{
[Key]
public Guid SimpleLineId { get; set; }
public int? ReferencePhotoId { get; set;}
[ForeignKey("ReferencePhotoId")]
public virtual DbReferencePhoto ReferencePhoto { get; set; }
public int? DropPhotoHorizontalLineId { get; set;}
[ForeignKey("DropPhotoHorizontalLineId")]
public virtual DbDropPhoto DropPhotoHorizontalLine { get; set; }
public int? DropPhotoVerticalLineId { get; set;}
[ForeignKey("DropPhotoVerticalLineId")]
public virtual DbDropPhoto DropPhotoVerticalLine { get; set; }
}