error 'there is already an open datareader associated with this command which must be closed first'

This can be easily solved by allowing MARS in your connection string. Add MultipleActiveResultSets=true to the provider part of your connection string (where Data Source, Initial Catalog, etc. are specified).

http://msdn.microsoft.com/en-us/library/h32h3abf(v=vs.100).aspx

error 'there is already an open datareader associated with this command which must be closed first'

原文：http://www.cnblogs.com/xixifusigao/p/3951033.html