参考：https://www.cnblogs.com/apple2016/p/8023196.html
db.GPRS_PRODUCT_HIS_FEE.find({"条件字段" : "412171211145135"},{'_id':0,"查询字段1":1,"查询字段1":1,"查询字段3":1,"查询字段4":1,"查询字段5":1,"查询字段6":1})
或者
db.GPRS_PRODUCT_HIS_FEE.find({"条件字段" : "412171211145135"},{"查询字段1":1,"查询字段2":1,"查询字段3":1,"查询字段4":1,"查询字段5":1,"查询字段6":1},{'_id':0})第二种情况，则输出所有字段，不包含_id