为什么我得到 ReferenceError: insertId is not defined on my 4th MySQL Query in NodeJS？答案

【问题标题】：Why do I get ReferenceError: insertId is not defined on my 4th MySQL Query in NodeJS?为什么我得到 ReferenceError: insertId is not defined on my 4th MySQL Query in NodeJS？
【发布时间】：2021-06-28 18:15:14
【问题描述】：

为什么我能够从第一个 MySQL 查询中获取 insertId，但不能在第四个查询的代码中进一步获取？查询有点复杂，但我不知道为什么第一次有效的东西在代码中后来不起作用；

var mysql   = require("mysql");
var express = require("express");
var connection = require("../database")    

 var createAudiopost = function(req, res, next){
     
 var title = req.body.title;
 var userid = req.body.userid;
 var opid = req.body.opid; 
 var tag1 = req.body.tag1;
     
connection.beginTransaction(function(err) {
  if (err) { throw err; }
  
connection.query('INSERT INTO ?? (title,userid,opid) VALUES (?, ?, ? )', ['audioposts',title,userid,opid], function(err, result) {
     if (err) { 
      connection.rollback(function() {
        throw err;
      });
    }

    var audioname = userid + '-' + result.insertId + '.m4a';
    var newid = result.insertId;    
    console.log("newid: "  , newid  );
    
    connection.query('UPDATE ?? SET audioname=? WHERE audioid = ?',  ['audioposts',audioname,newid], function (error, result, fields) {
      if (err) { 
        connection.rollback(function() {
          throw err;
        });
      }  
      
      if (tag1)  {  
        connection.query('SELECT tagid FROM tags WHERE tagname = ?', [tag1], function (error, result, fields) {                     
                  if (err) { 
                    connection.rollback(function() {
                      throw err;
                    });
                            }

        if (result < 1) {    
            connection.query('INSERT INTO tags SET tagname = ?', [tag1], function (error, result, fields) {
                      if (err) { 
                    connection.rollback(function() {
                          throw err;
                            });
                                }   
                                
                        console.log("lets see this wierd error", result);                                                               
                        const tagInsertId = result.insertId;                            
                        
            connection.query("INSERT INTO entitytag SET audioid = ?, tagid = ?, userid = ?", [insertId, tagInsertId, userId], function (error, result, fields) {
                      if (err) { 
                        connection.rollback(function() {
                          throw err;
                            });
                              }  

                connection.commit(function(err) {
                if (err) { 
                  connection.rollback(function() {
                    throw err;
                  });
                }
                 console.log('success!');
                 newid = result.insertId;
                 res.json({
                                "title" : title, 
                                "userid" : userid,
                                "opid" : opid, 
                                "insertid": newid
                        }); //resjson success               
                    }); //commit                  
                }); // insert entitytags
            }); // insert tags              
          } // if row
          
          else {                
                const tagid1 = result.tagid;                            
                connection.query("INSERT INTO entitytag SET audioid = ?, tagid = ?, userid = ?", [insertId, tagid1, userId], function (error, result, fields) {           
              if (err) { 
                connection.rollback(function() {
                  throw err;
                        }); //err
                        } //err 

                connection.commit(function(err) {
                if (err) { 
                  connection.rollback(function() {
                    throw err;
                  });
                }
                 console.log('success!');
                 res.json({
                                "title" : title, 
                                "userid" : userid,
                                "opid" : opid, 
                                "insertid": newid
                        }); //resjson success               
              }); //commit                          
            })  // insert entitytag2
          }   
        }); //select tagid
      }//tag1
    }); //update
  }); //insert
}); //begin transaction
}   //createaudiopost

   module.exports = createAudiopost;

代码到达;

 sql: "INSERT INTO tags SET tagname = 'dogmatism'"

但是之后我得到的错误是;

Parser.js:437
      throw err; // Rethrow non-MySQL errors
      ^    
ReferenceError: insertId is not defined

【问题讨论】：

标签： javascript mysql node.js node-mysql nodejs-server

【解决方案1】：

insertId 未定义，但用于以下查询：

connection.query("INSERT INTO entitytag SET audioid = ?, tagid = ?, userid = ?", [insertId, tagid1, userId], function (error, result, fields)

看起来您打算根据查询中的用法使用newid：

connection.query('UPDATE ?? SET audioname=? WHERE audioid = ?',  ['audioposts',audioname,newid], function (error, result, fields)

在此处替换相同的内容，它应该可以工作。

connection.query("INSERT INTO entitytag SET audioid = ?, tagid = ?, userid = ?", [newid, tagid1, userId], function (error, result, fields)

如果不创建一个名为 insertId 的变量并在使用它之前对其进行初始化。

【讨论】：