etl工作中的设计问题

insert overwrite table common.order
select
   userid
  ,case 
        when hour_time>=0  and hour_time<=2  then '00_03'
        when hour_time>=3  and hour_time<=5  then '03_06' 
        when hour_time>=6  and hour_time<=7  then '06_08'
        when hour_time>=8  and hour_time<=11  then '08_12'
        when hour_time>=12 and hour_time<=13  then '12_14'
        when hour_time>=14 and hour_time<=17  then '14_18'
        when hour_time>=18 and hour_time<=23  then '18_24'
        else '0'
      end 
        as hour_time 
   ,count(distinct dt) hour_dt_num
 where dt >='2014-10-01'
 and dt<='2014-10-30'
 group by userid,
 case when hour_time>=0  and hour_time<=2  then '00_03'
        when hour_time>=3  and hour_time<=5  then '03_06' 
        when hour_time>=6  and hour_time<=7  then '06_08'
        when hour_time>=8  and hour_time<=11 then '08_12'
        when hour_time>=12 and hour_time<=13 then '12_14'
        when hour_time>=14 and hour_time<=17 then '14_18'
        when hour_time>=18 and hour_time<=23 then '18_24'
        else '0'
      end 

#!/bin/bash
#
# add by lishc  2014-11-25
 
mysql=`which mysql`
user="root"
password="123"
database="test"
table="parm"
 
command="select par1,par2,id from test.$table "
$mysql -u${user} -p${password}  -e "${command}" >m.txt
 
###初始化
echo "       insert overwrite table common.order">mysql.sql
echo "               select     ">>mysql.sql
echo "                      userId  " >>mysql.sql
echo "                     case  ">>mysql.sql
 
sed -i -e '1d' m.txt
cat m.txt |while read line  
do
  par1=$(echo "${line}"|awk -F ' ' '{print $1}')
  par2=$(echo "${line}"|awk -F ' ' '{print $2}') 
  id=$(echo "${line}"|awk -F ' ' '{print $3}')  
   echo "par1: ${par1}"
   echo "par2: ${par2}"
   echo "                      when hour_time >=${par1}  and hour_time<=${par2}  then '${id}' ">>mysql.sql
Done