node_modules / mysql / lib / protocol / Parser.js：437 throw err; //抛出非MySQL错误

Question

我运行以下查询：

var updateTicketQuery = "UPDATE `tb_tickets` SET `status` = 0, second_gate_ip='"+_ip+"' WHERE `nationalcode` = '" + _barcode + "'";
                            //    console.log(updateTicketQuery)
                                db.query(updateTicketQuery) 


                                console.log("33")
                                _auth = 'disposable'
                                res.json({response:'barcode',success:'inTask',mode:'inTask',auth:_auth});
                                return false;

我的查询也执行，但是在响应时，我可以显示此错误消息（它应该返回我的res.json）：

33
/home/nodeser/node_modules/mysql/lib/protocol/Parser.js:437
      throw err; // Rethrow non-MySQL errors
      ^

Error: Can't set headers after they are sent.
    at ServerResponse.OutgoingMessage.setHeader (_http_outgoing.js:369:11)
    at ServerResponse.header (/home/nodeser/node_modules/express/lib/response.js:771:10)
    at ServerResponse.send (/home/nodeser/node_modules/express/lib/response.js:170:12)
    at ServerResponse.json (/home/nodeser/node_modules/express/lib/response.js:267:15)
    at Query.db.query (/home/nodeser/routes/Ticket.js:89:37)
    at Query.<anonymous> (/home/nodeser/node_modules/mysql/lib/Connection.js:525:10)
    at Query._callback (/home/nodeser/node_modules/mysql/lib/Connection.js:491:16)
    at Query.Sequence.end (/home/nodeser/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24)
    at Query._handleFinalResultPacket (/home/nodeser/node_modules/mysql/lib/protocol/sequences/Query.js:139:8)
    at Query.EofPacket (/home/nodeser/node_modules/mysql/lib/protocol/sequences/Query.js:123:8)