SQLSTATE[HY000] [1049] Unknown database 'blueyian'

Typecho_Db_Adapter_Exception: SQLSTATE[HY000] [1049] Unknown database 'blueyian' in /var/www/html/blueYian/var/Typecho/Db/Adapter/Pdo.php:60
Stack trace:
#0 /var/www/html/blueYian/var/Typecho/Db.php(198): Typecho_Db_Adapter_Pdo->connect(Object(Typecho_Config))
#1 /var/www/html/blueYian/var/Typecho/Db.php(349): Typecho_Db->selectDb(1)
#2 /var/www/html/blueYian/var/Typecho/Db.php(382): Typecho_Db->query(Object(Typecho_Db_Query), 1)
#3 /var/www/html/blueYian/var/Widget/Options.php(345): Typecho_Db->fetchAll(Object(Typecho_Db_Query), Array)
#4 /var/www/html/blueYian/var/Typecho/Widget.php(221): Widget_Options->execute()
#5 /var/www/html/blueYian/var/Widget/Init.php(31): Typecho_Widget::widget('Widget_Options')
#6 /var/www/html/blueYian/var/Typecho/Widget.php(221): Widget_Init->execute()
#7 /var/www/html/blueYian/index.php(17): Typecho_Widget::widget('Widget_Init')
#8 {main}