Question

我对SQL很陌生，我正在运行这样的东西来提取一些数据。但是目前我一次运行一个语句并将它们复制到excel。有没有办法一起运行所有这些？每个语句的级别相同，但count（ID）将不同。某些级别可能还有某些天没有任何数据。

select 
    count(ID), level 
from table1 
where createat >= "2013-11-22 00:00:00" and createat <= "2013-11-22 23:59:59" 
group by level;

select 
    count(ID), level 
from table1 
where createat >="2013-11-23 00:00:00" and createat <= "2013-11-23 23:59:59" 
group by level;

select 
    count(ID), level 
from table1 
where createat >= "2013-11-24 00:00:00" and createat <= "2013-11-24 23:59:59" 
group by level;

感谢您的帮助！我希望更多地了解如何编写这些内容。

Answer 1

SELECT
  level,
  COUNT(CASE WHEN createat>='2013-11-22' and createat<'2013-11-23' THEN id ELSE NULL END)   AS day_1_count,
  COUNT(CASE WHEN createat>='2013-11-23' and createat<'2013-11-24' THEN id ELSE NULL END)   AS day_2_count,
  COUNT(CASE WHEN createat>='2013-11-24' and createat<'2013-11-25' THEN id ELSE NULL END)   AS day_3_count
FROM
  table1
GROUP BY
  level
WHERE
  createat>='2013-11-22' and createat<'2013-11-25'

尽管如此，使用您需要的日期加入表格可能更有意义，而不是硬编码。

另外，请注意，SQL适用于固定数量的列，如果您想要一个查询3天然后重复使用5天，则不起作用。为此，您需要将其保留为每行一个结果。

Answer 2

试试这个：

SELECT t.level, SUM(CASE WHEN DATE(createat) = '2013-11-22' THEN 1 ELSE 0 END) AS day1,
       SUM(CASE WHEN DATE(createat) = '2013-11-23' THEN 1 ELSE 0 END) AS day2,
       SUM(CASE WHEN DATE(createat) = '2013-11-24' THEN 1 ELSE 0 END) AS day3
FROM table1 t
WHERE DATE(t.createat) >= "2013-11-22" AND DATE(t.createat) <= "2013-11-24" 
GROUP BY t.level;

或

SELECT t.level, SUM(CASE WHEN t.createat >= "2013-11-22 00:00:00" AND t.createat <= "2013-11-22 23:59:59" THEN 1 ELSE 0 END) AS day1, SUM(CASE WHEN t.createat >= "2013-11-23 00:00:00" AND t.createat <= "2013-11-23 23:59:59" THEN 1 ELSE 0 END) AS day2, SUM(CASE WHEN t.createat >= "2013-11-24 00:00:00" AND t.createat <= "2013-11-24 23:59:59" THEN 1 ELSE 0 END) AS day3 FROM table1 t WHERE t.createat >= "2013-11-22 00:00:00" AND t.createat <= "2013-11-24 23:59:59" GROUP BY t.level;

Answer 3

您发布的查询的简单编辑是：

select count(ID), level 
from table1 
where createat >= "2013-11-22 00:00:00" and createat <= "2013-11-22 23:59:59" 
group by level
union
select count(ID), level 
from table1 
where createat >="2013-11-23 00:00:00" and createat <= "2013-11-23 23:59:59" 
group by level
union
select count(ID), level 
from table1 
where createat >= "2013-11-24 00:00:00" and createat <= "2013-11-24 23:59:59" 
group by level

但是，如果您尝试获取每天的计数，级别值和日期，那么您可以使用如下查询：

SELECT COUNT(*), level, CAST(createat AS DATE)
FROM table1
GROUP BY level, CAST(createat AS DATE)

将多个sql语句组合到列中

3 个答案: