EF 实体关系

1. 基于共享主键的一对一：

   this.HasRequired(t => t.TRDConInfo)
   .WithOptional(t => t.TRDFoundationProjCheck);

2. 一对多

   this.HasRequired(t => t.ComponentBelong)
   .WithMany(t => t.TRDConInfos)
   .HasForeignKey(d => d.ComponentBelongID);

3. 多对多

   this.HasMany(t => t.Contract)
   .WithMany(t => t.DesignChangeAudit)
   .Map(m => {
   m.ToTable("T_Change_DesignAudit_Contract");
   m.MapLeftKey("DesignChangeAuditID");
   m.MapRightKey("ContractID");
   });