mysql - SQL 返回按条件分隔的行的 COUNT()

Question

我需要COUNT()（或者可能是另一个 MySQL 函数）我的查询行，但我需要不同的计数，如下所示：

我得到了什么：

   id  | date       | costumer_id
  -----+------- ----+-------------
   1   | 2012-10-05 | 103
   2   | 2012-10-05 | 103
   3   | 2012-10-05 | 103
   4   | 2012-10-05 | 59
   5   | 2012-10-05 | 59
   6   | 2012-10-05 | 90

我需要的：

   id  | date       | costumer_id | count
  -----+------------+-------------+------
   1   | 2012-10-05 | 103         | 3
   5   | 2012-10-05 | 59          | 2
   6   | 2012-10-05 | 90          | 1

Answer 1

您需要一个简单的按查询分组。我怀疑您将 id 留在 group by 中。尝试这样的事情：

select max(id), date, customer_id, count(*)
from t
group by date, customer_id
order by 1

Answer 2

SELECT id, `date`, customer_id, COUNT(1) AS `count`
FROM `table`
GROUP BY `customer_id`

Answer 3

你必须使用GROUP BY

以下查询将为您提供所需的结果：

选择 id、日期、costumer_id 、count(costumer_id) as c from table1 group by costumer_id order by c desc

Answer 4

select 
    min(id) as id, 
    date, 
    customer_id, 
    count(*) as count
from tatble
group by 
    date, 
    customer_id
order by 1;