Node connects to the database for addition, deletion, modification and query

//  The import module 
const mysql =require("mysql")
//  establish 
const db=mysql.createPool({
    host:"127.0.0.1",
    user:"root",
    password:"admin123",
    database:'my_db_01',
})
//  Check whether it is normal 
db.query('SELECT 1',(err,resulys)=>{
    if(err)return console.log(err)
    console.log(resulys)
})

// //  Insert 
// const user={username:'xue123114111',userpassword:'234441111'}
// //  perform sql  placeholder 
// const sqlStr1 ="insert into users(username,userpassword) values (?,?)"
// db.query(sqlStr1,[user.username,user.userpassword],(err,resulys)=>{
//     if(err) return console.log(err)
   
//     //  Data returned successfully 
//     if(resulys.affectedRows===1) console.log(" success ")

// })
// //  Portable insert 

// const user1={username:'qian',userpassword:'111111',status:'1'}
// const sqlStr2 ="insert into users set ?"
// db.query(sqlStr2,user1,(err,resulys)=>{
//     if(err) return console.log(err)
   
//     //  Data returned successfully 
//     if(resulys.affectedRows===1) console.log(" success ")

// })

//  Inquire about 
// const sqlStr="select * from  users"
// db.query(sqlStr,(err,resulys)=>{
//     if(err) return console.log(err)
//     console.log(resulys)
// })
//  Portable update 
const user1={ id:5,username:'xue',userpassword:'0000',status:'0'}
const sqlStr2 ='update  users set ? where id=?'
db.query(sqlStr2,[user1,user1.id],(err,resulys)=>{
    if(err) return console.log(err)
   
    //  Data returned successfully 
    if(resulys.affectedRows===1) console.log(" The update is successful ")

})
//  Delete 
const sqlStr3='delete from users where id=?'
db.query(sqlStr3,5,(err,results)=>{
   if(err) return console.log(err.message)
   if(results.affectedRows===1){
    console.log(" Delete data succeeded ")
   }
})