Fatal error: Uncaught think\db\exception\PDOException: SQLSTATE[3D000]: Invalid catalog name: 1046 No database selected in /www/wwwroot/996fn.com/vendor/topthink/think-orm/src/db/PDOConnection.php:797 Stack trace: #0 /www/wwwroot/996fn.com/vendor/topthink/think-orm/src/db/connector/Mysql.php(66): think\db\PDOConnection->getPDOStatement('SHOW FULL COLUM...') #1 /www/wwwroot/996fn.com/vendor/topthink/think-orm/src/db/PDOConnection.php(422): think\db\connector\Mysql->getFields('`prefix_user`') #2 /www/wwwroot/996fn.com/vendor/topthink/think-orm/src/db/PDOConnection.php(362): think\db\PDOConnection->getTableFieldsInfo('prefix_user') #3 /www/wwwroot/996fn.com/vendor/topthink/think-orm/src/db/PDOConnection.php(409): think\db\PDOConnection->getSchemaInfo('prefix_user') #4 /www/wwwroot/996fn.com/vendor/topthink/think-orm/src/db/PDOConnection.php(459): think\db\PDOConnection->getTableInfo('prefix_user', 'pk') #5 /www/wwwroot/996fn.com/vendor/topthink/think-orm/src/db/Query.php(290): think\db\PDOConnection->getPk('prefix_user') #6 in /www/wwwroot/996fn.com/vendor/topthink/think-orm/src/db/PDOConnection.php on line 797