1、测试没问题，上线一个功能老是报错
A second operation started on this context before a previous operation completed. This is usually caused by different threads using the same instance of DbContext.....
解决：检查代码是不是哪个异步方法调用遗漏了await关键字
原文：https://www.cnblogs.com/come-on-come-on/p/12410317.html