Description:
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when use prepare statment ,binding chinese string to ? or var return empty result .

Test script:
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$ora = new pdo("oci:dbname=//host:1521/racl;charset=zhs16gbk",$urp_user,$urp_pass,array(PDO::ATTR_PERSISTENT => false));
$sql = "select gh,xm from t where xm like ? order by xmpy";
$stmt = $ora ->prepare($sql);
$stmt->bindParam(1,strtoupper($_GET['xmpy'].'%');
$stmt->execute();
$r = $stmt->fetchAll(PDO::FETCH_ASSOC);

//$r = $ora->query_all("select gh,xm from t where xm like '".iconv('utf-8','gbk',$_GET['xmpy'])."%'");

file charset is utf-8.the build-in sql works fine