对象数组（getKeyObjects）

普通查询

$db = Be::getDb();

$sql = 'SELECT * FROM user WHERE age<18 AND sex=\'女\'';
$users = $db->getKeyObjects($sql, [], ‘id’);

foreach ($users as $id => $user) {
    // $id;
    // $user->name;
}

占位符查询

$db = Be::getDb();

$sql = 'SELECT * FROM user WHERE age<? AND sex=?';
$users = $db->getKeyObjects($sql, [18, '女'], ‘id’);

返回一个以 id 字段的值作为键名的对象数组，对象属性即查询结果中的字段