public function getTableComment(TableSchema $table, $indent = 0)
    {

        if (null === $this->_tableStatus) {
            try {
                // 不知 “SHOW TABLE STATUS” sql语句在其他数据库中是否会执行成功，所以用try catch捕获异常
                $this->_tableStatus = $this->db->createCommand('SHOW TABLE STATUS')->queryAll();
            } catch (\Exception $e) {
                return '';
            }
        }

        $textIndent = $this->textIndent($indent);
        $definition = $textIndent . '$this->runSuccess[\'addTableComment\'] = ';
        $tableName = static::removePrefix($table->name, $this->db->tablePrefix);

        foreach ($this->_tableStatus as $value) {
            if ($table->name === $value['Name'] && ! empty($value['Comment'])) {
                $comment = addslashes($value['Comment']);
                return $definition . "\$this->addCommentOnTable('{{%$tableName}}', '{$comment}');";
            }
        }

        return '';
    }