PHP PDO USE database 報錯問題筆記

PHP PDO連接配接MYSQL 切換資料庫報錯問題！

下面代碼出現警告：Warning: PDO::query(): SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOStatement::fetchAll(). Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.

$db = new PDO('mysql:host=localhost;port=3306;', dbuser, dbpass);
$db->query('USE `database`');
           

最終解決辦法：

$db->exec('USE `database`');
           

至于是什麼原因我也不清楚，希望有高人能夠補充.....