var mysql = require('mysql');
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "1111",
database: "crypto"
});
function get_date() {
con.connect(function () {
    con.query("SELECT * FROM btc", function (err, result, fields) {
    var array = [];
    var string = JSON.stringify(result);
    var json = JSON.parse(string);
    for (var i = 0; i < result.length; i++) {
        if (json[i].price != "null") {
            array.push(json[i].price)
        }
    }
    return array
   })
});

function getDate() {
    return new Promise((resolve) => {
        con.connect(() => {
            con.query(`SELECT * FROM btc`, (error, result, fields) => {
                const array = [];
                const string = JSON.stringify(result);
                const json = JSON.parse(string);
                for (let i = 0; i < result.length; i++) {
                    if (json[i].price != 'null') {
                        array.push(json[i].price);
                    }
                }
                resolve(array);
            });
        });
    });
}

getDate().then((array) => {
    console.log(array);
});