我在使用EF更新期间遇到以下错误:Theoperationfailed:Therelationshipcouldnotbechangedbecauseoneormoreoftheforeign-keypropertiesisnon-nullable.Whenachangeismadetoarelationship,therelatedforeign-keypropertyissettoanullvalue.Iftheforeign-keydoesnotsupportnullvalues,anewrelationshipmustbedefined,theforeign-keyproper

我在使用EF更新期间遇到以下错误:Theoperationfailed:Therelationshipcouldnotbechangedbecauseoneormoreoftheforeign-keypropertiesisnon-nullable.Whenachangeismadetoarelationship,therelatedforeign-keypropertyissettoanullvalue.Iftheforeign-keydoesnotsupportnullvalues,anewrelationshipmustbedefined,theforeign-keyproper

我的DbContext中有以下实体:publicclassA{publicA(){Bs=newList();}publicICollectionBs{set;get;}}有时我想更新一个图:vara=dbContext.As.AsNoTracking().Include(x=>x.Bs).firstOrDefault();varc=newC();a.Bs.Add(c);vard=newD();vare1=newE();vare2=newE();d.Es.Add(e1);//我想用它的B更新a(更新C,D,E也)使用graphdiff:dbContext.UpdateGraph(a,ma

我的DbContext中有以下实体:publicclassA{publicA(){Bs=newList();}publicICollectionBs{set;get;}}有时我想更新一个图:vara=dbContext.As.AsNoTracking().Include(x=>x.Bs).firstOrDefault();varc=newC();a.Bs.Add(c);vard=newD();vare1=newE();vare2=newE();d.Es.Add(e1);//我想用它的B更新a(更新C,D,E也)使用graphdiff:dbContext.UpdateGraph(a,ma