如何在 MySQL 中對日期字段進行分組以獲取季度結果？

Question

我有一個包含工作的工作表，leaddate 是工作條目的字段。

我想要得到的結果是我每個季度的工作數量。 我的查詢計算了leaddate 字段中每個日期的工作。

這是查詢

select count(jobid) as jobcount, leaddate
from jobs
where contactid='19249'
group by leaddate

Answer 1

我認為這應該做的工作：

SELECT YEAR(leaddate) AS year, QUARTER(leaddate) AS quarter, COUNT(jobid) AS jobcount
  FROM jobs
 WHERE contactid = '19249'
 GROUP BY YEAR(leaddate), QUARTER(leaddate)
 ORDER BY YEAR(leaddate), QUARTER(leaddate)

Answer 2

假設您有一個有效的日期或日期時間字段：

select count(jobid) as jobcount, YEAR(leaddate) yr, QUARTER(leaddate) qt
from jobs
where contactid='19249'
group by yr, qt

Answer 3

我通常將季度和年份組合成一個 YEAR-QUARTER 字段：

select jobid, count(jobid) as jobcount, 
CONCAT( YEAR(leaddate),'-',QUARTER(leaddate) ) as year_qtr
from jobs
where contactid='19249'
group by year_qtr

返回數據，如：

19249, 324, 2011-3
19249,   4, 2011-2
19249,  34, 2011-1

Answer 4

您可以使用 Quarter 函數從日期獲取季度：

select count(jobid) as jobcount, QUARTER(leaddate) as qt, YEAR(leaddate) as year
from jobs
where contactid='19249'
group by year,qt