顯示使用mysql表中的前一個和當前月份數據

Question

我想顯示同一列的三個不同的數字在mysql查詢中，我想保留一個月的靜態：四月，所以它會是這樣的情況我要顯示的當月，比上月和我一起工作的一年中靜月，在這種情況下，我們堅持2012

Example 
Tablename:payment 

    id , pay_date, amount 
    1 2012-02-12 1000 
    2 2012-03-11 780 
    3 2012-04-15 890 
    4 2012-05-12 1200 
    5 2012-06-12 1890 
    6 2012-07-12 1350 
    7 2012-08-12 1450 

所以我想要做的就是顯示列amount爲4月份，因爲我說我想保持這一行靜態：890，當前月份可以說當前月份是8月：1450和上個月將是7月份的金額：1350：因此最終結果會是這樣的：

april_amount current_month_amount previous_month_amount 
    890     1450     1350 

但是我在這裏卡住了：

select amount as april_amount 
from payment 
where monthname(pay_date) LIKE 'April' 
and year(pay_date) LIKE 2012 

我希望這個問題被寫足夠的清楚，非常感謝對大加讚賞的幫助。

Answer 1

我可能會離開這裏。但嘗試：

select top 1 
    p.amount, c.amount, n.amount 
from payment c 
    inner join payment p ON p.pay_date < c.pay_date 
    inner join payment n ON n.pay_date > c.pay_date 
where monthname(c.paydate) LIKE 'April' 
    and year(c.pay_date) LIKE 2012 
order by p.pay_date DESC, n.pay_date ASC 

編輯，我沒有正確地讀你的問題。我正在去往，現在和下個月。 1分鐘，我會再試一次。

select top 1 
    p.amount AS april_amount, c.amount AS current_month_amount, n.amount AS previous_month_amount 
from payment c 
    inner join payment p ON monthname(p.pay_date) = 'April' AND year(p.pay_date) = 2012 
    inner join payment n ON n.pay_date > c.pay_date 
where monthname(c.paydate) = monthname(curdate()) 
    and year(c.pay_date) = year(curdate()) 
order by n.pay_date ASC 

這假定每個月只有1個條目。

好的，所以我沒有寫在MySQL一段時間。這裏是您的示例數據什麼工作：

select 
    p.amount AS april_amount, c.amount AS current_month_amount, n.amount AS previous_month_amount 
from payment AS c 
    inner join payment AS p ON monthname(p.pay_date) LIKE 'April' AND year(p.pay_date) LIKE 2012 
    inner join payment AS n ON n.pay_date < c.pay_date 
where monthname(c.pay_date) LIKE monthname(curdate()) 
    and year(c.pay_date) LIKE year(curdate()) 
order by n.pay_date DESC 
limit 1 

比上月表連接的直覺相反命名n，但這個工程。我在WAMP安裝中驗證了它。

要處理每月的聚合，您可以使用子選擇。性能可能會受到非常大的表格影響（數百萬行或更多）。

SELECT SUM(a.amount) AS april_amount, 
(
    SELECT SUM(c.amount) 
    FROM payment c 
    WHERE MONTH(c.pay_date) = MONTH(CURDATE()) 
) AS current_month_amount, 
(
    SELECT SUM(p.amount) 
    FROM payment p 
    WHERE MONTH(p.pay_date) = MONTH(CURDATE() - INTERVAL 1 
    MONTH) 
) AS previous_month_amount 
FROM payment a 
WHERE MONTHNAME(a.pay_date) = 'April' 
AND YEAR(a.pay_date) =2012 

Answer 2

如果其結果可能是行，而不是列：

SELECT MONTHNAME(pay_date), amount FROM payment 

WHERE pay_date BETWEEN '2012-04-01' 
        AND '2012-04-30' 

    OR pay_date BETWEEN CURRENT_DATE 
         - INTERVAL DAYOFMONTH(CURRENT_DATE) - 1 DAY 
        AND LAST_DAY(CURRENT_DATE) 

    OR pay_date BETWEEN CURRENT_DATE 
         - INTERVAL DAYOFMONTH(CURRENT_DATE) - 1 DAY 
         - INTERVAL 1 MONTH 
        AND LAST_DAY(CURRENT_DATE - INTERVAL 1 MONTH) 

見它sqlfiddle。