过去 12 个月的 Mysql 总和

Question

我正在尝试创建一个查询以获取基于月份的最近 12 个月的记录以进行图表表示。经过大量阅读和观看此similar topic 之后，我创建了一个看似正确但缺少 0 钱月份的查询。例如，我在图表中看到月份 1/14、2/14、4/14 等等......缺少 3/14。

我的代码是这样的

SELECT *
FROM
    (SELECT DATE_FORMAT(now(), '%m/%y') AS Month
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 1 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 2 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 3 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 4 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 5 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 6 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 7 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 8 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 9 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 10 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 11 MONTH), '%m/%y')
    ) AS Months
LEFT JOIN
    (SELECT sum(expenses.price) AS ExpenseAmount,
            sum(payments.amount) AS PaymentsAmount,
            DATE_FORMAT(expenses.date_occurred,'%m/%y') AS Month,
            DATE_FORMAT(payments.date_occurred,'%m/%y') AS Montha
     FROM expenses,
          payments
     WHERE payments.user_id= 1
         AND payments.user_id=expenses.user_id
     GROUP BY MONTH(payments.date_occurred),
              YEAR(payments.date_occurred)
     ORDER BY payments.date_occurred ASC ) data ON Months.MONTH = data.Montha
ORDER BY data.Montha;

任何帮助都会很棒，因为这种查询对我来说太高级了:-)

Answer 1

由于查询看起来应该为每个月生成一行，您能否检查查询输出，而不是您的图表生成的内容？我怀疑你有一个 04/14 的条目，但值是 NULL 而不是 0。要纠正这个问题，你可以将查询更改为 start

SELECT Months.Month, 
    COALESCE(data.ExpenseAmount, 0) AS ExpenseAmount, 
    COALESCE(data.PaymentAmount, 0) AS PaymentAmount

COALESCE 会给你 0 而不是 NULL 没有匹配你的左连接的行。

但是，您的查询中还有其他问题。只有在同一个月有费用和付款时，您才会得到行 - 检查http://sqlfiddle.com/#!2/3f52a8/1，如果您从一个表中删除一些数据，您会看到问题。

这是一个可行的解决方案，它可以为您提供所有月份，将两个表中的数据相加，即使只有一个表存在。这通过将费用和付款作为单独的查询处理，然后将它们连接在一起来实现。

SELECT Months.Month, COALESCE(expensedata.ExpenseAmount, 0) AS ExpenseAmount, COALESCE(paymentdata.PaymentAmount, 0) AS PaymentAmount
FROM
    (SELECT DATE_FORMAT(now(), '%m/%y') AS Month
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 1 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 2 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 3 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 4 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 5 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 6 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 7 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 8 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 9 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 10 MONTH), '%m/%y')
     UNION SELECT DATE_FORMAT(DATE_SUB(now(), INTERVAL 11 MONTH), '%m/%y')
    ) AS Months

LEFT JOIN 
  (SELECT SUM(price) AS ExpenseAmount, DATE_FORMAT(date_occurred,'%m/%y') AS Month
   FROM expenses 
   WHERE user_id = 1
   GROUP BY MONTH(date_occurred), YEAR(date_occurred)) expensedata ON Months.Month = expensedata.Month

LEFT JOIN 
  (SELECT SUM(amount) AS PaymentAmount, DATE_FORMAT(date_occurred,'%m/%y') AS Month
   FROM payments
   WHERE user_id = 1
   GROUP BY MONTH(date_occurred), YEAR(date_occurred)) paymentdata ON Months.Month = paymentdata.Month

ORDER BY Months.Month;

显示此工作的 SQL Fiddle：http://sqlfiddle.com/#!2/3f52a8/5

Answer 2

我认为你的问题是左连接。您的左联接中的 select 语句的结果不包含任何 0 钱的结果...看起来像您的

where payments.user_id = 1 

问题是……

在以下链接下，您可以找到所有类型连接的解释...http://blog.codinghorror.com/a-visual-explanation-of-sql-joins/

希望对你有帮助

Answer 3

将ORDER BY data.Montha 替换为ORDER BY Months.MONTH

data.Montha 中没有“3/14”。