Async/Await を使います。
maria_update.js
#! /usr/bin/node
// ---------------------------------------------------------------// maria_update.js//// Jun/04/2020//// ---------------------------------------------------------------varmysql=require('mysql2')// ---------------------------------------------------------------functionget_current_date_proc(){consttoday=newDate()varddx=(1900+today.getYear())+"-"+(today.getMonth()+1)ddx+="-"+today.getDate()returnddx}// ---------------------------------------------------------------functionupdate_command_gen(id_in,population_in){consttoday=get_current_date_proc()varcommand="update cities set population = "+population_incommand+=" , date_mod = '"+today+"'"command+=" where id = '"+id_in+"'"console.log(command)returncommand}// ---------------------------------------------------------------asyncfunctionmain(id_in,population_in){constdotenv=require('dotenv')dotenv.config()constuser=`${process.env.user}`constpassword=`${process.env.password}`constdata_base=`${process.env.data_base}`varconn=awaitmysql.createConnection({host:'localhost',user:user,password:password,database:data_base})constcommand=update_command_gen(id_in,population_in)awaitconn.execute(command)conn.end()console.error("*** 終了 ***")}// ---------------------------------------------------------------console.error("*** 開始 ***")constid_in=process.argv[2]constpopulation_in=process.argv[3]console.log(id_in+"\t"+population_in)main(id_in,population_in)// ---------------------------------------------------------------実行コマンド
export NODE_PATH=/usr/lib/node_modules
./maria_update.js t3326 721539800