nodejs：本地nodejs连接mysql 实现 增、删、改、查

var mysql = require("mysql");
var connection = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "snowball",
    database: "runoob_test",
  });
  connection.connect((err)=>{
      if(err) throw err;
      console.log('链接成功')
  });

var mysql = require("mysql");
var connection = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "snowball",
    database: "runoob_test",
  });
  connection.connect((err)=>{
      if(err) throw err;
      console.log('链接成功')
  });
  // console.log('connection:', connection)
  // conn.query(sqlStr[,params],callback)
  // sqlStr:要执行的sql语句，可以使用占位符
  // params:参数列表，数组
  // callback:回调函数，第一个参数：异常对象；第二个参数：结果对象
  // SELECT * FROM要大写
  // 查询数据表runoob_tbl
  let sql = 'SELECT * FROM runoob_tbl'
  connection.query(sql, function (error, results, fields) {
    if (error) throw error;
    console.log('The solution is: ', results);
  });
  // https://www.runoob.com/nodejs/nodejs-mysql.html

var mysql = require("mysql");
var moment = require('moment');
var connection = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "snowball",
    database: "runoob_test",
  });
  connection.connect((err)=>{
      if(err) throw err;
      console.log('链接成功')
  });
  // console.log('connection:', connection)
  // conn.query(sqlStr[,params],callback)
  // sqlStr:要执行的sql语句，可以使用占位符
  // params:参数列表，数组
  // callback:回调函数，第一个参数：异常对象；第二个参数：结果对象
  // SELECT * FROM要大写
  // 查询
  // let sql = 'SELECT * FROM runoob_tbl'
  // connection.query(sql, function (error, results, fields) {
  //   if (error) throw error;
  //   console.log('The solution is: ', results);
  // });
  // 插入
  // 注意参数、值，个数要正确，格式要正确
  console.log(moment().format("YYYY-MM-DD HH:mm:ss"));
  // var  addSql = 'INSERT INTO runoob_tbl(runoob_id,runoob_title,runoob_author,submission_date) VALUES(2,?,?,?)';
  var  addSql = 'INSERT INTO test_tb2(title,name) VALUES(11,22)';
  // var  addSqlParams = ['菜鸟工具', 'https://c.runoob.com','23453'];
  connection.query(addSql,function (err, result) {
    if(err){
      console.log('[INSERT ERROR] - ',err.message);
        return;
    }
      console.log('INSERT-success');
  })
  // https://www.runoob.com/nodejs/nodejs-mysql.html

var mysql = require("mysql");
var moment = require('moment');
var connection = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "snowball",
    database: "runoob_test",
  });
  connection.connect((err)=>{
      if(err) throw err;
      console.log('链接成功')
  });
  var modSql = 'UPDATE test_tb2 SET title = ?,name = ?';
  var modSqlParams = ['nameTest', 'titleTest'];
  //改
  connection.query(modSql,modSqlParams,function (err, result) {
     if(err){
           console.log('[UPDATE ERROR] - ',err.message);
           return;
     }
    console.log('UPDATE affectedRows',result.affectedRows);
  });
  // https://www.runoob.com/nodejs/nodejs-mysql.html

var mysql = require("mysql");
var moment = require('moment');
var connection = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "snowball",
    database: "runoob_test",
  });
  connection.connect((err)=>{
      if(err) throw err;
      console.log('链接成功')
  });
  var delSql = 'DELETE FROM test_tb2 where title=title';
  //改
  connection.query(delSql,function (err, result) {
     if(err){
           console.log('[DELETE ERROR] - ',err.message);
           return;
     }
    console.log('DELETE affectedRows',result.affectedRows);
  });
  // https://www.runoob.com/nodejs/nodejs-mysql.html