mysql 中去掉字段类型为decimal中后面多余的0

//处理前
SELECT '0.12000','1.203010','-0.20'
//处理后
SELECT 0+CAST('0.12000' AS CHAR),0+CAST('1.203010' AS CHAR),0+CAST('-0.20' AS CHAR)
//ci框架
$this->db->select("0+CAST(price_now AS CHAR) as price_now");