我不能为我的生活弄清楚为什么实体框架(4.1,Code First)没有实现可选的导航属性。可选导航属性未加载
波苏斯:
public class PlanMember {
public Int64 Id { get; set; }
public String FirstName { get; set; }
public virtual SystemUser CaseManager { get; set; }
public String LastName { get; set; }
public virtual PlanMemberStatus Status { get; set; }
}
public class SystemUser {
public String EMail { get; set; }
public String FirstName { get; set; }
public String Id { get; set; }
public String LastName { get; set; }
}
public class PlanMemberStatus {
public Int32 Id { get; set; }
public String Code { get; set; }
}
配置类:
public class ForPlanMemberEntities:EntityTypeConfiguration<PlanMember> {
public ForPlanMemberEntities(String schemaName) {
this.HasOptional(e => e.CaseManager)
.WithMany()
.Map(m => m.MapKey("CaseManagerID"));
this.HasRequired(e => e.Status)
.WithMany()
.Map(m => m.MapKey("StatusID"));
this.ToTable("PlanMember", schemaName);
}
}
public class ForSystemUserEntities:EntityTypeConfiguration<SystemUser> {
public ForSystemUserEntities(String schemaName) {
this.ToTable("SystemUser", schemaName);
}
}
public class ForPlanMemberStatusEntities:EntityTypeConfiguration<PlanMemberStatus> {
public ForPlanMemberStatusEntities(String schemaName) {
this.ToTable("PlanMemberStatus", schemaName);
}
}
语境:
public class Context:DbContext {
public DbSet<PlanMember> PlanMemberDbSet { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
base.OnModelCreating(modelBuilder);
var schemaName = Properties.Settings.Default.SchemaName;
modelBuilder.Configurations
.Add(new Configuration.ForPlanMemberEntities(schemaName))
.Add(new Configuration.ForPlanMemberStatusEntities(schemaName))
.Add(new Configuration.ForSystemUserEntities(schemaName))
;
}
}
基础上的conf配置,如果我运行如下查询它不会填充CaseManager
属性。 PlanMemberStatus
属性加载得很好。
var test = (from member in PlanMemberDbSet
where member.CaseManager != null
select member).First();
var cm = test.CaseManager;
在我的例子cm
总是null
,尽管事实是 - 从逻辑上说 - 这应该是不可能的。有什么想法吗?
编辑 - 如果我做PlanMemberDbSet.Include("CaseManager")
那么它按预期工作。为什么这是必要的?在其他情况下,我不必这样做。
你的第一段是100%正确的。 'PlanMember'表的值都是大写的,'SystemUser'表的值都是小写的。一旦我把它们变成两个相同的情况,它就会神奇地起作用。绝对是一个错误,国际海事组织。 – Yuck