modify

Database/Connection.php

@@ -265,6 +265,8 @@ class Connection extends Component
      */
     public function createCommand($sql = null, array $attributes = []): Command
     {
+        $sql = preg_replace('/FROM\s+(\w+)\s+/', 'FROM ' . $this->database . ' $1', $sql);
+
         $command = new Command(['db' => $this, 'sql' => $sql]);
         return $command->bindValues($attributes);
     }

System/Pool/Connection.php

@@ -127,7 +127,6 @@ class Connection extends Pool
         }
         /** @var PDO $connections */
         $connections = $this->getFromChannel($coroutineName, $config);
-        $connections->query('use `' . $config['database'].'`');
         if ($number = Context::getContext('begin_' . $coroutineName, Coroutine::getCid())) {
             $number > 0 && $connections->beginTransaction();
         }