官方文档 https://www.php.net/manual/zh/pdostatement.bindparam.php
注意:
bindParam 第2个参数 mixed &$variable 是引用传值
正确的用法 ($val by reference):
<?php foreach ($params as $key => &$val) { $sth->bindParam($key, $val); } ?>
错误的用法 ($val by value, because bindParam needs &$variable):
<?php foreach ($params as $key => $val) { $sth->bindParam($key, $val); }