将四个不同的查询合并为一个

Question

假设我有这四个查询：

SELECT id_cre as credito, 
    data_eff as data, 
    '0.00' as incasso, 
    importo_fatt as spesa 
from fatture 
WHERE data_eff < '2014-12-31' 
UNION
SELECT id_cre as credito, 
    data_prev as data, 
    '0.00' as incasso, 
    importo_fatt as spesa 
from fatture 
WHERE data_prev >= '2014-12-31' 
UNION 
SELECT id_cre as credito, 
    data_prev as data, 
    importo as incasso, 
    '0.00' as spesa 
from incassi_prev 
WHERE data_prev >= '2014-12-31' 
UNION 
SELECT id_cre as credito, 
    data_inc as data, 
    importo_inc as incasso, 
    '0.00' as spesa 
from incassi_row 
WHERE data_inc < '2014-12-31'

我用它们提取代码 (credito)、日期 (data) 和金额），可以是收入 (incasso) 或支出 (spesa)。

结果可能会创建重复的行（具有相同代码但一次有收入而另一次有支出的行）。如何重写查询以将具有相同代码和日期的收入和支出放在同一行？我想用 mysql 来做，因为我已经需要遍历 javascript 中的结果数组来按行重写 table （每个代码作为一行，每个月作为一个列）。

此外，有没有什么办法可以做到同样的事情，但考虑到同一日期在同一 month/year 中的两个不同日期（例如 2014-12-20 和 2014-12-31）

谢谢！

Answer 1

尝试

SELECT credito, data, SUM(incasso) AS incasso, SUM(speca) AS speca
  FROM
(
  SELECT id_cre AS credito, data_eff AS data, 0.0 AS incasso, importo_fatt AS spesa 
    FROM fatture 
   WHERE data_eff < '2014-12-31' 
   UNION
  SELECT id_cre AS credito, data_prev AS data, 0.0 AS incasso, importo_fatt AS spesa 
    FROM fatture 
   WHERE data_prev >= '2014-12-31' 
   UNION 
  SELECT id_cre AS credito, data_prev AS data, importo AS incasso, 0.0 AS spesa 
    FROM incassi_prev 
   WHERE data_prev >= '2014-12-31' 
   UNION 
  SELECT id_cre AS credito, data_inc AS data, importo_inc AS incasso, 0.0 AS spesa 
    FROM incassi_row 
   WHERE data_inc < '2014-12-31'
) q
GROUP BY credito, data

将四个不同的查询合并为一个

merge four different queries in one

mysql