实体框架将“System.Data。EntityException:底层的提供者没有打开。“移动10k+记录。”

I have an application where I move data from one table to another on the same database (some simple calculations are done). I use the entity framework to select the data from the first table and add it to the other table.I try to transfer appx. 100k rows and the problem is that it seems like it kills the connection to my database. After it has been running for a while I get the error below. Does anyone have a clue why that might happen? NB. I am running on ms 2008 express.I have an application where I move data from on