_id必须明确排除。例如，
Transaction.find({username : user.username}, { '_id': 0, 'uniqueId' :1, 'timeout': 1, '/confirm/iation_link': 1, 'item_name': 1}, function(err, txs){ console.log("user : " + user.username + " with txs: " + txs); callback(txs);});
_id必须明确排除。例如，
Transaction.find({username : user.username}, { '_id': 0, 'uniqueId' :1, 'timeout': 1, '/confirm/iation_link': 1, 'item_name': 1}, function(err, txs){ console.log("user : " + user.username + " with txs: " + txs); callback(txs);});名师互学网 版权所有 (c)2021-2022 ICP备案号：晋ICP备2021003244-6号
