開發程式遇到奇怪的問題，批次程式中設定了多組排程，當不同排程同時使用Entity Framework 做Query，會出現錯誤訊息以下：
System.Data.Entity.Core.EntityException: The underlying provider failed on Open. --->
System.InvalidOperationException: The connection was not closed. The connection's current state is connecting.
2018-05-04
