从查询中获取所有分组字段

我需要group by从查询https://play.golang.org/p/5h_IExbQb_D获取所有字段

package main

import (
    "fmt"
    "regexp"
)

func main() {
query := `SELECT sum(a) as a, count(b) as b, c as c, d as d, e as e
    FROM table
    group by c, d, e order by c`
    re := regexp.MustCompile(`(group by) ((.)*,?)*`)
    fmt.Printf("%q\n", re.FindAll([]byte(query), -1))

}

它返回：

["group by c, d, e order by c"]

但是预期的输出是

["c, d, e"]