我在之前的迁移中添加了它,现在数据库是最新的,我想添加其他更改。我做错了什么? PM> Add-Migration Northwind1.3
Build started...' because a property or navigation with the same name already exists on entity type 'AdoNet.Entities.EF.Employee<BuildModel>b__0_31(EntityTypeBuilder b) in D:\Programming\Cshar