modify

Database/Base/BaseActiveRecord.php

@@ -1060,7 +1060,7 @@ abstract class BaseActiveRecord extends Component implements IOrm, ArrayAccess
     {
         return static::getDb()->getSchema()
             ->getColumns()
-            ->table(static::getTable());
+            ->table('`' . static::getDbName() . '`.' . static::getTable());
     }
 
     /**

Database/Connection.php

@@ -265,6 +265,7 @@ class Connection extends Component
      */
     public function createCommand($sql = null, $dbname = '', array $attributes = []): Command
     {
+        if (!empty($dbname)) {
             $substr = strtoupper(substr($sql, 0, 6));
             $sql = match ($substr) {
                 'SELECT', 'SHOW F', 'DELETE' => preg_replace('/FROM\s+(\w+)\s+/', 'FROM `' . $dbname . '`.$1 ', $sql),
@@ -274,6 +275,7 @@ class Connection extends Component
                 default => throw new Exception('database error')
             };
             $sql = preg_replace('/INNER JOIN\s+(\w+)\s/', 'INNER JOIN `' . $dbname . '`.$1 ', $sql);
+        }
         $command = new Command(['db' => $this, 'sql' => $sql]);
         return $command->bindValues($attributes);
     }