PHP - 从 MySQL 数据库中回显某些内容 [重复]

Question

我想，我的 PHP 代码可能需要帮助... 我试图在 MySQL 数据库中回显信息，它给了我错误：Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in /usr/local/ampps/www/php/db.php on line 18

我的代码是：

<?php
$servername = "blabla"; //changed, connecting works
$username = "blabla";
$password = "blabla";
$database = "blabla";

// Create connection
$conn = new mysqli($servername, $username, $password, $database);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
} else {
echo "Connection success \n";
}

$sql = mysql_query("SELECT * FROM Schueler");
while($data = mysql_fetch_array($sql)) //This is line 18...
{
echo "ID: " . $data['ID'] . " Vorname: " . $data['Vorname'] . " Nachname: " . $data['Nachname'] . " Klasse: " . $data['Klasse'] . "<br>";
}

$conn->close();

?>

如果有人可以帮助我会很好:)

编辑：

我只使用 MySqli 修复了它，这是我现在的工作代码：

// Create connection
$conn = new mysqli($servername, $username, $password, $database);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} else {
  echo "Connection success  \n";
}

$sql = "SELECT ID, Vorname, Nachname FROM Schueler";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["ID"]. " - Name: " . $row["Vorname"]. " " . $row["Nachname"]. "<br>";
    }
} else {
    echo "0 results";
}
$conn->close();

感谢您的快速建议。

Answer 1

您已使用 mysqli 进行连接设置，然后使用简单的 mysql 函数来获取结果集和 fetch_array 逻辑。在这种情况下，您需要保持统一。

我已将mysql_query() 调用更改为mysqli_query() 调用，同样将mysql_fetch_array() 调用更改为mysqli_fetch_array() 调用。

最终代码变成：

$sql = mysqli_query("SELECT * FROM Schueler", $conn);
while($data = mysqli_fetch_array($sql)) 
{
echo "ID: " . $data['ID'] . " Vorname: " . $data['Vorname'] . " Nachname: " . $data['Nachname'] . " Klasse: " . $data['Klasse'] . "<br>";
}