每天的 hsqldb 计数

Posted 2023-04-19

【中文标题】每天的 hsqldb 计数

【英文标题】：hsqldb count for each day

【发布时间】：2013-06-02 09:27:44

【问题描述】：

有桌子

id|date|somefield

我需要计算一年中每一天的条目数

select EXTRACT (DAY_OF_YEAR FROM date) as day, id from table

工作正常

但是当我尝试时

select EXTRACT (DAY_OF_YEAR FROM date) as day, count(*) from table

失败

select count(*) from table group by EXTRACT (DAY_OF_YEAR FROM date)

同样失败

【问题讨论】：

怎么样，select EXTRACT (DAY_OF_YEAR FROM date) as day, count(*) from tableGROUP BY EXTRACT (DAY_OF_YEAR FROM date)？

水失败了？你有错误还是什么？如果是什么错误

【参考方案1】：

您需要添加一个group by 表达式。这是一些伪代码，我稍后会编写一个 SqlFiddle。

select EXTRACT (DAY_OF_YEAR FROM date) as day, 
count(*) 
from table
group by EXTRACT (DAY_OF_YEAR FROM date)

SQLFIDDLE（使用 MYSQL） http://sqlfiddle.com/#!2/42c9e/10