PHP一页上的2个SQL查询

Question

我正在尝试使以下页面正常工作。 我过去有类似的页面可以正常工作，但是它们只包含一个sql查询。 请查看以下代码，并告诉我您的想法。 我试图使代码尽可能简单，并希望这可能是一个基本的语法错误。 谢谢

<?php
session_start();

$servername = "localhost";
$username = "digita86_Hyperius";
$password = "5xtc55xtc!";
$dbname = "digita86_2_cent_rally_db";

$connection = new mysqli($servername, $username, $password, $dbname);

if ($connection->connect_error) {
    die("Connection failed: " . $connection->connect_error);
}

$passcodeInput = $_POST['passcode'];

$query = "SELECT * FROM 2_cent_rally_db_table WHERE email='$passcodeInput'";

$result = mysqli_query($connection, $query) or die(mysqli_error($connection));

$count = mysqli_num_rows($result);

if ($count == 1){

$_SESSION['passcode'] = $passcodeInput;

}else{

echo "I'm sorry but the credentials you have submitted do not match our records. Please try again.";
}
?>
<?
$servername = "localhost";
$username = "digita86_Hyperius";
$password = "5xtc55xtc!";
$dbname = "digita86_2_cent_rally_db";

$connectionA = new mysqli($servername, $username, $password, $dbname);

$queryA = "SELECT * FROM 2_cent_rally_db_table WHERE email='$passcodeInput'";

$resultA = mysqli_query($connectionA, $queryA);

$rowA = mysqli_fetch_array($resultA);

$rowA['balance'];

$dicecoinBalance = $rowA['balance'];

echo $dicecoinBalance;

$_SESSION['balance'] = $dicecoinBalance;

if ($connectionA->connect_error) {
    die("Connection failed: " . $connectionA->connect_error);
?>
<?
$servername = "localhost";
$username = "digita86_Hyperius";
$password = "5xtc55xtc!";
$dbname = "digita86_2_cent_rally_db";

$connectionB = new mysqli($servername, $username, $password, $dbname);

$queryB = "SELECT * FROM 2_cent_rally_db_table WHERE email='$passcodeInput'";

$resultB = mysqli_query($connectionB, $queryB);

$rowB = mysqli_fetch_array($resultB);

$rowB['stock_value'];

$stockValue = $rowB['stock_value'];

echo $stockValue

$_SESSION['stock_value'] = $stockValue;

if ($connectionB->connect_error) {
    die("Connection failed: " . $connectionB->connect_error);

header("Location: 2_cent_rally.php");


$connection->close();
?>

Answer 1

您无需在每次查询时都创建新的mysqli连接，可以使用$ connection-> query（$ query），这将返回一个包含数据的映射。