Unknown database 'koa'

FILE: /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/Db.class.php 　LINE: 162

[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/Db.class.php (162) DbMysql->connect()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Driver/Db/DbMysql.class.php (94) Db->initConnect()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Driver/Db/DbMysql.class.php (213) DbMysql->query(SHOW COLUMNS FROM `cms_article`)
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/Model.class.php (135) DbMysql->getFields(cms_article)
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/Model.class.php (123) Model->flush()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/Model.class.php (1174) Model->_checkTableInfo()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/Model.class.php (98) Model->db(0, )
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Common/common.php (272) Model->__construct(article)
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/index/Lib/Action/IndexAction.class.php (15) D(article)
[26-10-11 15:39:10] () IndexAction->index()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/App.class.php (171) ReflectionMethod->invoke()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/App.class.php (207) App::exec()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Lib/Core/Think.class.php (39) App::run()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/Common/runtime.php (242) Think::start()
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/core/core.php (30) require(/home/wwwroot_php/www_itying_com/koa/core/Common/runtime.php)
[26-10-11 15:39:10] /home/wwwroot_php/www_itying_com/koa/index.php (19) require(/home/wwwroot_php/www_itying_com/koa/core/core.php)