如果使用的是Code First,使用update database -verbose完成了miragtion 之后,运行发现异常:
Validation failed for one or more entities. See 'EntityValidationErrors' property for more details
这是由于migration对model的更改导致了db中column的限制(例如长度,StringLength(30)会导致nvarchar(max)变为nvarchar(30))
想要看到异常的具体信息,可以catch DbEntityValidationException :
try
{
// Your code...
// Could also be before try if you know the exception occurs in SaveChanges
context.SaveChanges();
}
catch (DbEntityValidationException e)
{
foreach (var eve in e.EntityValidationErrors)
{
}
}