Mysql：JOIN 2表中，SUM之一不正確

Question

這是兩個表的結構

表A

+----+-----+----+----------------------+--------------------+----------+
| id | ... |....|   time_start         | time_end           |  total   | 
+----+-----+----+----------------------+--------------------+----------+
  1               2015-12-06 10:00:00    2015-12-06 12:00:00     200
  2               2015-12-07 10:00:00    2015-12-07 12:00:00     300              

表B

+----+----------+------+------+------+------+
| id | idTableA | val1 | val2 | val3 | val4 |   
+----+----------+------+------+------+------+
  1        1       10     10     10     10
  2        1       10     10     10     10
  3        2       10     10     10     10

目標如下：給定一個time_start和一個time_end date，顯示總計的總和（表A）和val1，val2，val3，val4的總和

范例 ：

• time_start = 2015-12-01 00:00:00

• time_end = 2015-12-30 23:59:59

預期結果 ：總計= 500，val（1-4）等於120

我已經嘗試過了：

$myquery = "";
$myquery .= "SELECT SUM(tableA.total) AS myTotal,";
$myquery .= "SUM(tableB.val1) + SUM(tableB.val2) + SUM(tableB.val3) + SUM(tableB.val4) AS myValTotal ";
$myquery .= "FROM tableA INNER JOIN tableB ON tableA.id = tableB.idTableA ";
$myquery .= "WHERE tableA.time_start >='".$dateStart."' AND tableA.time_end <='".$dateEnd."'";

val（1-4）的SUM正確，但合計的SUM不正確。

Answer 1

您必須檢查想要重疊的數據范圍是部分還是全部。

確定兩個日期范圍是否重疊

最好的測試方法是首先直接在數據庫上復制查詢。

在WHERE檢查數據范圍

SET @dateStart= '2015-12-01 00:00:00';
SET @dateEnd = '2015-12-30 23:59:59';

SELECT myTotal, myValTotal 
FROM 
    (
      SELECT SUM(tableA.total) AS myTotal
      FROM tableA
      WHERE tableA.time_start >= @dateStart
        AND tableA.time_end <=  @dateEnd ;
    ) T1
CROSS JOIN 
    (
        SELECT SUM(tableB.val1 + tableB.val2 + tableB.val3 + tableB.val4) AS myValTotal 
        FROM tableA 
        INNER JOIN tableB 
                ON tableA.id = tableB.idTableA
        WHERE tableA.time_start >= @dateStart
          AND tableA.time_end <=  @dateEnd
   ) T2;

Answer 2

您不應該在行的乘法上進行匯總。 而是獨立地聚合兩個表，然后將它們聯接起來，例如：

select * from
(
SELECT SUM(tableA.total) AS myTotal
FROM tableA 
WHERE tableA.time_start <= @dateEnd 
  AND tableA.time_end >=  @dateStart
) x join (
SELECT SUM(tableB.val1) + SUM(tableB.val2) + 
       SUM(tableB.val3) + SUM(tableB.val4) AS myValTotal 
FROM tableB join  tableA ON tableA.id = tableB.idTableA
WHERE tableA.time_start <= @dateEnd 
  AND tableA.time_end >=  @dateStart
) y;

Answer 3

作為起點，這似乎更容易閱讀...

$myquery = 
 "
 SELECT SUM(a.total) myTotal
      , SUM(b.val1 + b.val2 + b.val3 + b.val4) myValTotal
   FROM tableA a
   JOIN tableB b
     ON b.idTableA = a.id 
  WHERE a.time_start >='$dateStart' 
    AND a.time_end   <='$dateEnd'
 ";

Answer 4

SELECT  
SUM(tableB.val1) + SUM(tableB.val2) + SUM(tableB.val3) + SUM(tableB.val4) AS myValTotal,
(SELECT SUM(total) from tableA  where   tableA.time_start >='2015-12-01 00:00:00' AND tableA.time_end <= '2015-12-30 23:59:59') as myTotal 
FROM tableA  INNER JOIN tableB ON tableA.id = tableB.idTableA 
WHERE tableA.time_start >='2015-12-01 00:00:00' AND tableA.time_end <= '2015-12-30 23:59:59'

Answer 5

在加入數據之前先匯總數據，這樣您就不會誤認為值是多重的。

select sum(a.total) as mytotal, sum(b.sumval) as myvaltotal
from tablea a
left join
(
  select idtablea, sum(val1+val2+val3+val4) as sumval
  from tableb
  group by idtablea
) b on b.idtablea = a.id
where a.time_start >= @start and a.time_end <= @end;

這與SELECT子句中的子查詢相同。 它更簡單，可以繞開Juan Carlos Oropeza在以下評論中描述的問題。

select 
  sum(total) as mytotal, 
  sum((
    select sum(val1+val2+val3+val4)
    from tableb
    where idtablea = tablea.id
  )) as sumvaltotal
from tablea
where time_start >= @start and time_end <= @end;

Answer 6

您可以聲明int類型的變量並存儲總和值，然后再次對存儲的值求和以獲得總值

          declare  @val1 int
          declare @val2 int
          declare @val3 int
          declare @val4 int
          declare @newval int

            select @val1= SUM(isnull(val1,0)) , @val2 =
            sum(isnull(val2,0)), @val3=sum(isnull(val3,0)),@val4 = 
            sum(isnull(val2,0)) from TableB

            select @newval = @val1 +@val2+@val3+@val4

@newval將包括val1與val4之和