comment

\n COMMENT方法 用于在生成的SQL语句中添加注释内容，例如：\n\n~~~\nDb::table('think_score')->comment('查询考试前十名分数')\n ->field('username,score')\n ->limit(10)\n ->order('score desc')\n ->select();\n~~~\n最终生成的SQL语句是：\n\n~~~\nSELECT username,score FROM think_score ORDER BY score desc LIMIT 10 \n~~~\n