php – pdo动态绑定asc / desc命令

假设我有2个pdo语句,只是顺序不同(asc与desc)

$stmt1 = $po->prepare("SELECT * FROM tabname WHERE categ=:categ ORDER BY field1 DESC");
$stmt2 = $po->prepare("SELECT * FROM tabname WHERE categ=:categ ORDER BY field1 ASC");

有没有办法可以动态绑定ASC / DESC,所以我只能有1 stmt

$order = "ASC"; //or "DESC"

$stmt = $po->prepare("SELECT * FROM tabname WHERE categ=:categ ORDER BY field1 order=:order");
$stmt->bindParam(':order', $order, PDO::ParaM_STR);

解决方法:

没有.参数自动引用,不应引用ASC / DESC.这与表和列名称不能是参数的原因相同.