Question

我正在尝试使用部分余额进行查询，其中最后一列是一行一行：

此处有一组数据 A ，日期为DD-MM-YYYY

Amount | Date       
20     | 16-01-2013
 -1     | 22-01-2013
 -2     | 22-01-2013
 -3     | 23-01-2013
-9    | 24-01-2013

这里有一组数据 B

Amount | Date       
-5     | 23-01-2013
 -4     | 23-01-2013
 9     | 23-01-2013
 3     | 24-01-2013
-3    | 24-01-2013

我想得到这样的结果，让我们说一下数据集A：

Amount | Date | Balance

-9 | 24-01-2013 | 14
-3  | 23-01-2013 | 17
-2  | 22-01-2013 | 19
-1 | 22-01-2013 | 20
20  | 16-01-2013 | 0

我正在对这两个数据集使用此查询：

  SELECT
    PreAgg.tData,
    PreAgg.amount,
    @PrevBal := @PrevBal - PreAgg.amount AS Total
FROM
    (
        SELECT
            pr.tData,
            pr.amount

        FROM
            tableTest pr
        ORDER BY
            pr.tData desc
    ) AS PreAgg,
    (SELECT @PrevBal := 0.00) AS SqlVars

对于数据集B来说，它对于数据集A是完美的，但它没有，我无法理解为什么！

非常感谢

解

嗨，最后我设法做到了。

我在这里使用假计数器查询：

 SELECT
 reference,amount,balance
 FROM
 (
 SELECT
 @id := @id + 1 AS id,t.date as reference,t.amount,
 @balance := (@balance + t.amount) AS balance
 FROM
 tmpTable t, (SELECT @id:=0, @balance:=0, @grouping:=0) AS vars
 ORDER BY
 t.tData
 ) AS x
 ORDER BY
 x.id DESC

Answer 1

如果我将日期解释为DD-MM-YYYY，您的结果才有意义。否则，日期会出现乱码。

假设日期存储为日期（而不是字符串），您需要“asc”而不是“desc”：

SELECT (@rownumIn :=amount+@rownumIn) AS Balance, date, amount
FROM table_data cross join
     (SELECT @rownumIn := 0
     ) AS counter
WHERE some constraits
ORDER BY date asc;

我怀疑你犯了将日期存储为字符串的罪行。如果是这种情况，可以使用str_to_date()：

轻松修复

SELECT (@rownumIn :=amount+@rownumIn) AS Balance, date, amount
FROM table_data cross join
     (SELECT @rownumIn := 0
     ) AS counter
WHERE some constraits
ORDER BY str_to_date(date, '%d-%m-%Y') asc;

如何在SQL中逐行创建部分余额

1 个答案: