Conseils sur l'utilisation des fonctions d'exploitation de la base de données PHP

mysqli mysqli_connect ( string $host , string $username , string $passwd , string $dbname [, int $port = 3306 [, string $socket = '' ]] )

// 连接数据库
$mysqli = mysqli_connect("localhost", "root", "password", "mydatabase");

// 检查连接是否成功
if (!$mysqli) {
    die("Connection failed: " . mysqli_connect_error());
}
echo "Connected successfully";

mixed mysqli_query ( mysqli $link , string $query [, int $resultmode = MYSQLI_STORE_RESULT ] )

$sql = "SELECT id, name FROM users";
$result = mysqli_query($mysqli, $sql);

if (mysqli_num_rows($result) > 0) {
    while($row = mysqli_fetch_assoc($result)) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";
    }
} else {
    echo "0 results";
}

// 插入数据
$sql = "INSERT INTO users (name, age) VALUES ('John', 25)";
if (mysqli_query($mysqli, $sql)) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . mysqli_error($mysqli);
}

// 更新数据
$sql = "UPDATE users SET age=30 WHERE name='John'";
if (mysqli_query($mysqli, $sql)) {
    echo "Record updated successfully";
} else {
    echo "Error updating record: " . mysqli_error($mysqli);
}

// 删除数据
$sql = "DELETE FROM users WHERE id=3";
if (mysqli_query($mysqli, $sql)) {
    echo "Record deleted successfully";
} else {
    echo "Error deleting record: " . mysqli_error($mysqli);
}

mysqli_stmt mysqli_prepare ( mysqli $link , string $query )

$sql = "SELECT id, name, age FROM users WHERE age > ?";
$stmt = mysqli_prepare($mysqli, $sql);

if ($stmt) {
    mysqli_stmt_bind_param($stmt, "i", $age);
    $age = 20;
    mysqli_stmt_execute($stmt);
    mysqli_stmt_bind_result($stmt, $id, $name, $age);

    while (mysqli_stmt_fetch($stmt)) {
        echo "id: " . $id . ", name: " . $name . ", age: " . $age;
    }

    mysqli_stmt_close($stmt);
} else {
    echo "Error in preparing statement: " . mysqli_error($mysqli);
}

// 关闭自动提交事务
mysqli_autocommit($mysqli, FALSE);

// 执行多个SQL语句
mysqli_query($mysqli, "INSERT INTO users (name, age) VALUES ('John', 25)");
mysqli_query($mysqli, "UPDATE users SET age=30 WHERE name='John'");

// 如果所有SQL语句都成功执行，则提交事务
mysqli_commit($mysqli);
echo "Transaction committed successfully";

// 如果任何一个SQL语句执行失败，则回滚事务
mysqli_rollback($mysqli);
echo "Transaction rolled back because of failure";

// 关闭数据库连接
mysqli_close($mysqli);
echo "Connection closed";