sql周期统计

表table1 有id result 字段 假设1000条记录：
  20110601 open
  20110602 close
.......................
  20111600 open

现要统计某一周期参数内open close个数对比，然后存进另一个表table2，假设每300条：
字段:
  start end open close interval
 20110601 20110900 150 160 300
 20110901 20111200 140 160 300
 20111201 20111500 144 156 300
 .....................................
 最后剩余的100条记录
 20111501 20111600 60 40 100

若周期参数为200
  start end open close interval
 20110601 20110800 100 100 200
 20110801 20111000 80 120 200
 20111001 20111200 140 60 200
...........................................
 20111401 20111600 100 100 200

请问查询语句写法？（最好一次查询能完成）
 

Select (id-1) div 300,min(id) as start ,max(id) as end,
Sum(if(result=’open’,1,0)) as open,
Sum(if(result=’close’,1,0)) as close,
300 as ` interval`
From table1
Group by (id-1) div 300