com.ibatis.common.jdbc.exception.NestedSQLException:   
--- The error occurred while applying a parameter map.  
--- Check the home.getBookBestList-InlineParameterMap.  
--- Check the statement (query failed).  
--- Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '3938' for key 'group_key'