我有一个类似于下面的列的表,但有大约 30 个日期列和 500 多条记录
id | forcast_date | actual_date
1 10/01/2013 12/01/2013
2 03/01/2013 06/01/2013
3 05/01/2013 05/01/2013
4 10/01/2013 09/01/2013
我需要做的是得到一个输出类似于
week_no | count_forcast | count_actual
1 4 6
2 5 7
3 2 1
ETC
我的查询是
SELECT weekofyear(forcast_date) as week_num,
COUNT(forcast_date) AS count_forcast ,
COUNT(actual_date) AS count_actual
FROM
table
GROUP BY
week_num
但我得到的是每列中重复的 forcast_date 计数,即
week_no | count_forcast | count_actual
1 4 4
2 5 5
3 2 2
任何人都可以告诉我制定查询以获得我需要的最佳方式吗?
谢谢