Validation failed for one or more entities. See 'EntityValidationErrors' property for more details.

来源:http://www.cnblogs.com/sh_yao/p/4225719.html

当出现

Validation failed for one or more entities. See 'EntityValidationErrors' property for more details.

时,

dubug追踪 ((System.Data.Entity.Validation.DbEntityValidationException)$exception) . 可以看到是哪个字段出了什么问题. 我这里出现的原因是,user字段原来是20,因为服务器名原因,改到100. C#代码中,EF相关代码没有改全,一个mapping文件,一个是EF总的XML.