code: public function actionFlushSchema($db = 'db')
      {
          $connection = Yii::$app->get($db, false);
          if ($connection === null) {
              $this->stdout("Unknown component \"$db\".\n", Console::FG_RED);
              return ExitCode::UNSPECIFIED_ERROR;
          }
  
          if (!$connection instanceof \yii\db\Connection) {
              $this->stdout("\"$db\" component doesn't inherit \\yii\\db\\Connection.\n", Console::FG_RED);
              return ExitCode::UNSPECIFIED_ERROR;
          } elseif (!$this->confirm("Flush cache schema for \"$db\" connection?")) {
              return ExitCode::OK;
          }
  
          try {
              $schema = $connection->getSchema();
              $schema->refresh();
              $this->stdout("Schema cache for component \"$db\", was flushed.\n\n", Console::FG_GREEN);
          } catch (\Exception $e) {
              $this->stdout($e->getMessage() . "\n\n", Console::FG_RED);
          }
      }
docs: Clears DB schema cache for a given connection component.
  
  ```
  # clears cache schema specified by component id: "db"
  yii cache/flush-schema db
  ```
  
  @param string $db id connection component
  @return int exit code
  @throws Exception
  @throws \yii\base\InvalidConfigException
  
  @since 2.0.1