Export Data from Mysql to Multiple CSV Files - page by page

export.js

const mysql = require("mysql");
const fastcsv = require("fast-csv");
const Json2csvParser = require("json2csv").Parser;
const fs = require("fs");
var pool  = mysql.createPool({
    connectionLimit : 10,
    host: "host",
    user: "root",
    password: "",
    database: "master",
    multipleStatements: true
  });


//



const  getAllLeads=async (page)=>{

    const limit = 5000;
    const offset = (page - 1) * limit

    const leadQry = "select * from leads L limit "+limit+" OFFSET "+offset
   
    pool.getConnection(function(err, connection) {
      connection.query(leadQry, function (error, results, fields) {
        // When done with the connection, release it.
        connection.release();
        let jsonFinal=[];
        if(error) throw(error);
        results.forEach(lead=>{

        try{

            if(lead.lead_fields!=''){
            let lead_fields=JSON.parse(lead.lead_fields);
            let jsonDataFinal={supplier_id:lead.supplier_id,email_id:lead.email_id,...lead_fields,timestamp:lead.created,id:lead.id};
            jsonFinal.push(jsonDataFinal);
            }
        }catch(ex){
            console.log(lead);
            process.exit();
        }

        });

            const json2csvParser = new Json2csvParser({ header: true});
            const csv = json2csvParser.parse(jsonFinal);
            fs.writeFile(`./${page}_results.csv`, csv, function(error) {
            if (error) throw error;
            console.log(`Exporting page : ${page}`);
            });


      })
    })
  }



(async ()=>{
  
 //no of pages to export
for(k=1;k<=168;k++){
   await getAllLeads(k);
}
})();