public static function getSampleStandardNum($where)
{
self::initDB();
$sql = "select * from " . self::$table . " {$where}";
$query = self::$dbConn->query($sql);
if ($query) {
$ret = self::$dbConn->num_rows($query);
return $ret;
//成功， 返回列表数据
} else {
self::$errCode = "003";
self::$errMsg = "444444444";
return false;
//失败则设置错误码和错误信息， 返回false
}
}