test2.php

<?php
error_reporting(-1);
ini_set('display_errors', 1);

$conn = null;

// Acquire DB connection
$servername = "localhost";
$username = "hcvwvprmyw";
$password = "bqcX3PaeBb";
$dbname = "hcvwvprmyw";

try {    
    global $conn;

        $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
        // set the PDO error mode to exception
        $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    
} catch(PDOException $e) {
            die("Error: " . $e->getMessage());
}

function saveToDb($data) {
    global $conn;

    $name = $data['name'];
    $pair = $data['pair'];
    $buy = $data['buy'];
    $sell = $data['sell'];
    $total_trade = $data['total_trade'];
    $rec_date = date("Y-m-d H:i:s");

    $stmt = $conn->prepare("INSERT INTO coins (name, pair, buy, sell, total_trade, rec_date) 
    VALUES (:name, :pair, :buy, :sell, :total_trade, :rec_date)");

    $stmt->bindParam(':name', $name);
    $stmt->bindParam(':pair', $pair);
    $stmt->bindParam(':buy', $buy);
    $stmt->bindParam(':sell', $sell);
    $stmt->bindParam(':total_trade', $total_trade);
    $stmt->bindParam(':rec_date', $rec_date);

    $stmt->execute();


    // return "Good Job!! Records Inserted";

}

/**
**  Call the poloniex API to get all coins available
**
**/
$coins = file_get_contents('currencies.json');

// Convert JSOn resource to object
$coins = json_decode($coins);

// Convert object to array
$coins = json_decode(json_encode($coins), true);

$data = array();

            // Loop through coins array to get details for each coin
foreach ($coins as $key => $coin) {
    $s = array();

    $coin_delisted = $coin['delisted'];

    $coin_disabled = $coin['disabled'];


  // drop delisted coins
    if ((!$coin_delisted)) {
         // drop disabled coins
        if ((!$coin_disabled)) {
            $i = 1;

            // Get the coin abbreviation example Bitcoin (BTC), Ethereum (ETH)
            $currency = $key;

            // Form a currency pair with the abbreviation example BTC_ETH
            $currencypair = "BTC_".$key;
            // array_push($s, "pair => $currencypair");
            $s["pair"] = $currencypair;

            //Get coin name
            $coin_name = $coin['name'];
            // array_push($s, "name => $coin_name");
            $s["name"] = $coin_name;

            //Get current time in UNIX timestamp
            $now = time();

            //Go 24hrs back
            // Changed to 10 mins - 24hrs was returning error when I was testing. Took time to discover.
            $then = $now - 600;

            /**
                    **  Call the poloniex API to get all trade history for the currency pair
                    **
                    **/
            $trades = file_get_contents("https://poloniex.com/public?command=returnTradeHistory&currencyPair=$currencypair&start=$then&end=$now");

            // Convert JSOn resource to object
            $trades = json_decode($trades);

            // Convert object to array
            $trades = json_decode(json_encode($trades), true);

            // Initialize trade buy and trade sell
            $trade_buy = 0;
            $trade_sell = 0;

            // Loop through trade history to get details for each currency pair
            foreach ($trades as $key => $trade) {
                // Check if the type of trade done is a buy or a sell
                if ($trade['type'] == "buy") {
                  // if trade is buy increment trade_buy
                    $trade_buy = $trade_buy + 1;
                } elseif ($trade['type'] == "sell") {
                  // if trade is sell increment trade_sell
                    $trade_sell = $trade_sell + 1;
                }
            }
                    
                            //    array_push($s, "buy => $trade_buy");
                            $s["buy"] = $trade_buy;
                            //    array_push($s, "sell => $trade_sell");
                            $s["sell"] = $trade_sell;

                            $s['total_trade'] = $trade_buy + $trade_sell;
                            
                            //saveToDb($s);

                            array_push($data, $s);
                            // $data[$i] = $s;

                
             $i++;
        }
    }
}

usort($data, function ($a, $b) {
    return $a['total_trade'] <=> $b['total_trade'];
});

// In reverse/descending order
$data = array_reverse($data);

// cast to json
$json = json_encode($data, true);

echo $json;


// try {

//     $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
//     // set the PDO error mode to exception
//     $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
//     $stmt = $conn->prepare("INSERT INTO coins (name, pair, buy, sell, rec_date) 
//     VALUES (:name, :pair, :buy, :sell, :rec_date)");

//     $stmt->bindParam(':name', $name);
//     $stmt->bindParam(':pair', $pair);
//     $stmt->bindParam(':buy', $buy);
//     $stmt->bindParam(':sell', $sell);
//     $stmt->bindParam(':rec_date', $rec_date);

//     // insert another row
//     $name = "KAY";
//     $pair = "BTC_KAY";
//     $buy = 230;
//     $sell = 300;
//     $rec_date = NOW();
//     $stmt->execute();

//     //foreach($data as $row)
//    // {
//     //    $stmt->execute(array(
//    //         "name" => $row['name'],
//    //         "pair" => $row['pair'],
//    //         "buy" => $row['buy'],
//    //         "sell" => $row['sell'],
//    //         "rec_date" => NOW(),
//    //     ));
//     //} 

//     echo "Good Job!! Records Inserted";

    
//     } catch(PDOException $e) {
//     echo "Error: " . $e->getMessage();
//     }

$conn = null;

?>