Can't create component 'xxx.xxx.xxx' as it has dependencies to be satisfied

问题描述：

Can't create component 'xxx.xxx.xxx' as it has dependencies to be satisfied.

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 问题原由：

没有对新建的实体映射类创建对应的数据库表。

执行add-migration  xxx      update-database

在add-migration前一定要在DbContext中去配置即将映射的实体。搞忘了