Question

我正在尝试创建一个执行以下操作的SQL语句，但显然是失败了。

从视图中选择所有信息并根据以下条件对其进行过滤：

如果表格中的任何一点存在给定字段“customer_number”
然后检查过去30天内是否有任何重复
然后输出按customer_number
有计数，以便我可以看到项目被重复多少次。

因此，使用今天作为我们当前的日期说我在表格中有以下数据条目：

customer_number, date
111111, 2013-01-01
111111, 2013-05-05
222222, 2013-01-07
222222, 2013-03-19
333333, 2013-05-15
333333, 2013-05-30

我希望我的SELECT语句返回以下内容：

customer_number, date, count
111111, 2013-01-01, 2
333333, 2013-05-15, 2

客户222222将不会显示，因为他没有出现在过去30天内。

就我已经试图解决这个问题而言。它只返回当月的数据。

SELECT *, COUNT(customer_number) 
FROM red_flags 
WHERE dealer_id = '75' AND date BETWEEN CURDATE() - INTERVAL 30 DAY AND CURDATE() 
GROUP BY customer_number 
HAVING COUNT(customer_number) > 1

我一直在融化我的大脑，试图弄清楚在查询中如何甚至可以做任何帮助都会非常感激！

Answer 1

这样的事情对你有用 - 它使用子查询来找出过去30天内被标记的客户。然后，它使用COUNT获取总数，MIN获取第一个日期。

SELECT customer_number, COUNT(1), MIN(date) minDate
FROM red_flags 
WHERE customer_number IN (
  SELECT customer_number
  FROM red_flags
  WHERE dealer_id = '75' 
      AND date BETWEEN CURDATE() - INTERVAL 30 DAY AND CURDATE() 
  )
GROUP BY customer_number

如果您只关心具有多个记录的那些，您可以添加HAVING子句。

SQL Fiddle Demo

顺便说一句，小心使用BETWEEN和日期。我更喜欢明确并使用＆gt; =和＆lt; =来获得更多控制权。

编辑 - 也许是最简单的解决方案，使用带有CASE的COUNT：

SELECT customer_number, COUNT(1), MIN(date) minDate
FROM red_flags 
GROUP BY customer_number 
HAVING COUNT(CASE WHEN date BETWEEN CURDATE() - INTERVAL 30 DAY AND CURDATE() THEN 1 END) > 0

More Fiddle

Answer 2

以下是使用JOIN

的方法

select r.customer_number, count(*) ct, min(date) minDate
from red_flags r
join (select distinct customer_number
      from red_flags
      where dealer_id = '75'
      and date between CURDATE() - INTERVAL 30 DAY and CURDATE()) x
ON r.customer_number = x.customer_number
group by customer_number
HAVING ct > 1

SQLFIDDLE

复杂的SQL Select语句

2 个答案: