JAVASCRIPT

mysql query node.js

const mysql=require('mysql2')

const connection = mysql.createPool({
    host: 'localhost',
    user:'root',
    password:'whatever it is',
    database: "whatever it is"
})

const sqlInsert = 'INSERT INTO reviews (fieldName1, fieldName2) values (?, ?)' // whatever query you want
connection.query(
  sqlInsert,
  [value1, value2], // inserts into '?' symbol
  (err, results, fields) => {
    if(err){
      console.log(err)
    }
    else{
      console.log(results)
    }
  }
)

nodejs mysql query

//The second form .query(sqlString, values, callback) comes when using placeholder values 
connection.query('SELECT * FROM `books` WHERE `author` = ?', ['David'], function (error, results, fields) {
  // error will be an Error if one occurred during the query
  // results will contain the results of the query
  // fields will contain information about the returned results fields (if any)
});

//The third form .query(options, callback) comes when using various advanced options on the query
connection.query({
  sql: 'SELECT * FROM `books` WHERE `author` = ?',
  timeout: 40000, // 40s
  values: ['David']
}, function (error, results, fields) {
  // error will be an Error if one occurred during the query
  // results will contain the results of the query
  // fields will contain information about the returned results fields (if any)
});

nodejs mysql

// you can't connect to mysql in client side js

// but you can use it in nodejs which is server-side
// for nodejs you can use package named mysql2
npm i mysql2

// read Doc here 
// https://www.npmjs.com/package/mysql2