Question

我正在尝试计算2014年每个月的约会数量，其中日期格式为'22 -JAN-14' 到目前为止，我已经尝试了这两个代码的变体，并且都提出了“YEAR”：无效的标识符。

代码1

SELECT count(*), MONTH(dateofappointment) as month, YEAR(dateofappointment) as year
FROM appointment
GROUP BY month
HAVING YEAR(dateofappointment) ='14'
ORDER BY month;

和CODE 2

select count(*)
from appointment
group by month(dateofappointment)
having year(dateofappointment) = '14';

感谢任何帮助。

Answer 1

使用Extract参考

SELECT EXTRACT(month FROM dateofappointment) "Month", count(*)
FROM appointment
WHERE EXTRACT(YEAR FROM dateofappointment) = '2014'
GROUP BY EXTRACT(month FROM dateofappointment)
ORDER BY EXTRACT(month FROM dateofappointment);

要有月份名称而不是数字

SELECT TO_CHAR(TO_DATE(EXTRACT(month FROM dateofappointment), 'MM'), 'MONTH') "Month", count(*)
FROM appointment
WHERE EXTRACT(YEAR FROM dateofappointment) = '2014'
GROUP BY EXTRACT(month FROM dateofappointment)
ORDER BY EXTRACT(month FROM dateofappointment);

Answer 2

你的年份应该是一个整数此外，除非您的约会发生在第一世纪，否则您的年份应该是2014年。

试试这个：

select  EXTRACT(month FROM dateofappointment), count(*)
from appointment
where EXTRACT(year FROM dateofappointment) = 2014
group by EXTRACT(month FROM dateofappointment)

Answer 3

按月和年的数据，按日期从最旧到最新排序：

SELECT
    EXTRACT(year FROM dateofappointment) "Year",
    EXTRACT(month FROM dateofappointment) "Month",
    count(*) 
FROM
    appointment 
GROUP BY
    EXTRACT(year FROM dateofappointment),
    EXTRACT(month FROM dateofappointment) 
ORDER BY
    1,
    2;

每月计算记录

3 个答案: