When I delete a domain class called China in the rlinq file,How to restore this deleted file？

[PEIYANG]

I use “update from database" ,but it still failed! The "China" domain class can not be seen in rlinq file,but can be see in the Mapping detail editors! I want to see it in the rlinq file.
here is the picture 

[ABC]

delete the table in model schema explorer will be ok