SQLSTATE[HY000] [2002] Connection refused in .../Api/Controller/IndexController.php:72

FILE: /mnt/wwwroot/vendor/library/phpex/Common/functions.php 　LINE: 248

#0 /mnt/wwwroot/yun.jeechange.com/app/core.php.cache(2840): throws('SQLSTATE[HY000]...', '/mnt/wwwroot/yu...', 72, 2002)
#1 /mnt/wwwroot/yun.jeechange.com/app/core.php.cache(2954): phpex\DModel\DModel->throws(Object(PDOException), Array)
#2 /mnt/wwwroot/yun.jeechange.com/app/Api/Controller/IndexController.php(72): phpex\DModel\DModel->findOneBy(Array)
#3 [internal function]: Api\Controller\IndexController->main()
#4 /mnt/wwwroot/yun.jeechange.com/app/core.php.cache(147): ReflectionMethod->invokeArgs(Object(Api\Controller\IndexController), Array)
#5 /mnt/wwwroot/yun.jeechange.com/app/core.php.cache(1030): phpex\Library\App->run('Index', 'main', Array)
#6 /mnt/wwwroot/yun.jeechange.com/app/core.php.cache(755): phpex\Library\Route->dispatch()
#7 /mnt/wwwroot/yun.jeechange.com/www/index.php(17): phpex\Library\Main->run()
#8 {main}