Fatal error: Uncaught InvalidArgumentException: Undefined db config:yzb_db in /data/mystack/sites/www.ckw.gx.cn/www/vendor/topthink/think-orm/src/DbManager.php:248 Stack trace: #0 /data/mystack/sites/www.ckw.gx.cn/www/vendor/topthink/think-orm/src/DbManager.php(261): think\DbManager->getConnectionConfig('yzb_db') #1 /data/mystack/sites/www.ckw.gx.cn/www/vendor/topthink/think-orm/src/DbManager.php(233): think\DbManager->createConnection('yzb_db') #2 /data/mystack/sites/www.ckw.gx.cn/www/vendor/topthink/think-orm/src/DbManager.php(216): think\DbManager->instance('yzb_db', false) #3 [internal function]: think\DbManager->connect('yzb_db') #4 /data/mystack/sites/www.ckw.gx.cn/www/vendor/topthink/think-orm/stubs/Facade.php(63): call_user_func_array(Array, Array) #5 /data/mystack/sites/www.ckw.gx.cn/www/phpcms/modules/yzb/exam.php(24): think\Facade::__callStatic('connect', Array) #6 /data/mystack/sites/www.ckw.gx.cn/www/phpcms/libs/classes/application.class.php(56): exam->__construct() #7 /data/mystack/sites/www.ckw.gx.cn/www/ph in /data/mystack/sites/www.ckw.gx.cn/www/vendor/topthink/think-orm/src/DbManager.php on line 248