在准备好的PDO mysql查询中结合使用数组和单个元素

// 假设已经建立了PDO数据库连接对象 $pdo

// 使用数组构建查询条件
$conditions = [
    'name' => 'John',
    'age' => 25,
    'gender' => 'male'
];

$sql = "SELECT * FROM users WHERE";
$params = [];

foreach ($conditions as $key => $value) {
    $sql .= " $key = :$key AND";
    $params[":$key"] = $value;
}

$sql = rtrim($sql, ' AND');

$stmt = $pdo->prepare($sql);
$stmt->execute($params);
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);

// 使用单个元素构建查询条件
$name = 'John';

$sql = "SELECT * FROM users WHERE name = :name";

$stmt = $pdo->prepare($sql);
$stmt->bindParam(':name', $name);
$stmt->execute();
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);