请教一句sql

Question

表结构以及记录：
+--------------+----------+---------------------+-----------+-------------+-----
--------+--------+---------+----------+--------+--------+----------+-------+
| chanceitemId | chanceId | contactTime         | linkmanId | contactKind | cont
actMode | userId | content | nextTime | chance | volume | saleTime | phase |
+--------------+----------+---------------------+-----------+-------------+-----
--------+--------+---------+----------+--------+--------+----------+-------+
|           66 |       26 | 2010-12-23 17:23:00 |         0 |         509 |
      0 |      0 | a2      | NULL     |      0 |   NULL | NULL     |     0 |
|           67 |       26 | 2010-12-07 17:23:00 |         0 |         509 |
      0 |      1 | a1      | NULL     |      0 |   NULL | NULL     |     0 |
|           73 |       27 | 2010-12-28 17:24:00 |         0 |         509 |
      0 |      0 | b1      | NULL     |     30 |    123 | NULL     |     0 |
|           74 |       27 | 2010-12-29 17:24:00 |         0 |         509 |
      0 |      0 | b2      | NULL     |      0 |   1234 | NULL     |     0 |
|           75 |       27 | 2010-12-30 17:25:00 |         0 |         509 |
      0 |      3 | b3      | NULL     |      0 |   NULL | NULL     |     0 |
+--------------+----------+---------------------+-----------+-------------+-----
--------+--------+---------+----------+--------+--------+----------+-------+目的，查该表中，各个chanceId对应的最近一次contactTime的记录以及该chanceId对应的chanceitem记录数。
使用了以下的sql：
select chanceitemId,count(chanceitemId) as cnt,chanceId,contactTime,content,nextTime,chance,volume, saleTime from t_cust_chanceitem group by chanceId having contactTime in (select Max(contactTime) from t_cust_chanceitem GROUP by CHANCEID);但是得不到chanceId=27的记录值，请问该如何写这句sql？

Answer 1

select chanceitemId,count(*),chanceId,contactTime,content,nextTime,chance,volume, saleTime 
from (
select *
from t_cust_chanceitem
Order By contactTime DESC
) t
group by chanceId

Answer 2

原来的语句根本不对。你需要了解
select chanceitemId,count(chanceitemId) as cnt,chanceId,contactTime,content,nextTime,chance,volume, saleTime from t_cust_chanceitem group by chanceId
的结果是什么？
然后再执行 having contactTime in (select Max(contactTime) from t_cust_chanceitem GROUP by CHANCEID);判断。