The entity type 'XXX' requires a primary key to be defined. If you intended to use a keyless entity type call 'HasNoKey()'

.NET Core使用EF時 報錯如下信息：
The entity type 'XXX' requires a primary key to be defined. If you intended to use a keyless entity type call 'HasNoKey()'

源代碼為：
Model.DataModelContext _context = new Model.DataModelContext();

_context.業務方法();

 

改為如下即可：

using(Model.DataModelContext _context = new Model.DataModelContext())

{

_context.業務方法();

}