SQL条件分组和求和

时间:2011-12-06 01:27:32

标签: sql tsql group-by sybase-iq

我的数据如下:

|cat |subcat |amount|
---------------------
|A   |1      |123   |
|A   |2      |456   |
|B   |1      |222   |
|B   |2      |333   |

在第一种情况下,我需要用cat和subcat求和。易:

SELECT cat, subcat, sum(amount) FROM data GROUP BY cat, subcat

接下来,我有一个更复杂的要求,对于某些猫,应该将数量“推”到给定的子猫中。这可以存储在另一个config表中:

|cat |subcat|
-------------
|B   |1     |

这告诉我,对于所有cat='B'行,金额应被视为subcat=1。此外,cat='B' AND subcat <> 1的数量应报告为零。换句话说,我需要的结果是:

|cat |subcat|amount|
|A   |1     |123   |
|A   |2     |456   |
|B   |1     |555   |
|B   |2     |0     |

我无法更新数据表。当然我可以在proc中SELECT ... INTO并在那里修复数据,但我想知道它是否可以在一次点击中完成。

我可以非常接近:

SELECT data.cat,
    ISNULL(config.subcat, data.subcat),
    SUM(amount)
FROM data
    LEFT OUTER JOIN config ON (data.cat = config.cat)
GROUP BY data.cat, ISNULL(config.subcat, data.subcat)

...但是我的第二个要求是将cat:B, subcat:2显示为零。

有可能吗?

我正在使用Sybase IQ 12.5(即旧的T-SQL,但是有case语句,我怀疑它可能有用)

6 个答案:

答案 0 :(得分:1)

这就是我想出的。

SELECT cat, subcat, sum(amount)
FROM
(
    SELECT d.cat,
        d.subcat,
        CASE WHEN c.subcat <> d.subcat THEN 0 ELSE amount END amount
    FROM data d
        LEFT OUTER JOIN config c ON (d.cat = c.cat)
    UNION    
    SELECT d.cat,
        ISNULL(c.subcat, d.subcat),
        amount
    FROM data d
        LEFT OUTER JOIN config c ON (d.cat = c.cat)
    WHERE c.subcat <> d.subcat
) AS data2
GROUP BY cat, subcat

鉴于它使用带有union的派生表,并且我的实际数据集比我在问题中提供的数据集大得多,我认为SELECT ... INTO后跟更新可能实际上更高效接近!

答案 1 :(得分:1)

您需要使用连接Data -> Config -> Data将B2转换为B1,然后将UNION转换为带有Case语句的SELECT,然后将SUM和GROUP BY转换为

SELECT
   t.CAT, 
   t.SUBCAT, 
   SUM(t.AMOUNT) AMOUNT
FROM
(
SELECT d.cat, 
       d.subcat, 
       CASE 
         WHEN c.subcat IS NULL 
               OR c.subcat = d.subcat THEN d.amount 
         ELSE 0 
       END AS amount 
FROM   data d 
       LEFT JOIN config c 
         ON d.cat = c.cat 

UNION ALL 

SELECT d.cat, 
       d.subcat, 
       d2.amount 
FROM   data d 
       INNER JOIN config c 
         ON ( d.cat = c.cat ) 
       INNER JOIN data d2 
         ON c.cat = d2.cat 
            AND c.subcat <> d2.subcat 
            AND c.subcat = d.subcat 
) t
GROUP BY
    cat,
    subcat
ORDER BY
    cat,
    subcat
​

您可以在此data.se query看到一个有效的例子。

注意我添加了第三个“B”值来测试多个卷起SubCat的位置

另一种使用WITH和ROLLUP子句的方法(Sybase的某些版本支持哪些我不知道哪个)

with g as ( 
    SELECT 

        d.cat, 
        d.subcat,
        c.subcat config_subcat, 
        sum(amount) amount,
        GROUPING(c.subcat) subcatgroup
    FROM   data d 
    LEFT JOIN config c
    ON d.cat = c.cat 

   GROUP BY
      d.cat, 
      d.subcat,
      c.subcat with rollup
)

SELECT
   g.cat, 
   g.subcat,
   case when g.config_subcat is null then g.amount 
     WHEN g.subcat = g.config_subcat THEN g2.amount 
     ELSE 0 end amount
FROM g 

     LEFT JOIN g g2
     ON g.cat = g2.cat and g2.subcatgroup= 1
     and g.subcat is not null and g2.subcat is null

WHERE g.subcatgroup= 0​​

可在此data.se query

查看

答案 2 :(得分:0)

我对这些要求感到有点困惑,但我认为这就是你想要的。

SELECT d.cat,
       d.subcat, 
       SUM(CASE 
           WHEN c.subcat IS NULL OR c.subcat = d.subcat 
           THEN d.amount 
           ELSE 0 
        END) as Amount
FROM @Data d
    LEFT OUTER JOIN @Config c ON (d.cat = c.cat)
GROUP BY d.cat, d.subcat
ORDER BY d.cat

此处示例 - http://data.stackexchange.com/stackoverflow/q/120507/

请告诉我这是不是你想要的。

答案 3 :(得分:0)

我正在使用tsql,这是我的代码。这很丑,但有效。实际上,我喜欢你非常接近的方法(如果你不坚持显示B2 = 0)。

SELECT A.cat,
       A.subcat,
       CASE WHEN B.IsConfig = 0 THEN A.amount
            WHEN B.IsConfig = 1 AND C.cat IS NULL THEN 0
            ELSE B.amount 
       END AS amount
FROM data A
INNER JOIN 
(
    SELECT B1.cat, B1.amount, CASE WHEN C1.cat IS NULL THEN 0 ELSE 1 END AS IsConfig
    FROM
    (
        SELECT cat, SUM(amount) amount
        FROM data
        GROUP BY cat
    ) B1 LEFT OUTER JOIN config C1 ON B1.cat = C1.cat
) B ON A.cat = B.cat
LEFT OUTER JOIN config C ON A.cat = C.cat AND A.subcat = C.subcat

---我不能评论别人,所以我在这里添加我的问题---

使用执行计划将我的代码与其他代码进行比较,我的查询成本为46%。这是否意味着它更有效率?或者它只取决于:)

答案 4 :(得分:0)

为派生表中“config”中引用的所有“cat”计算SUM(amount),然后根据需要将其与“data”表条目匹配:

   SELECT data.cat,
          data.subcat,
          CASE 
            WHEN dt.subcat IS NULL       -- no "config" entry for cat
              THEN data.amount
            WHEN dt.subcat = data.subcat -- "config" for cat and subcat
              THEN dt.total
            ELSE 0                       -- "config" for cat not subcat
          END AS amount
     FROM data
LEFT JOIN (  SELECT config.cat,
                    config.subcat,
                    SUM(data.amount) AS total
               FROM config
               JOIN data USING (cat)
           GROUP BY 1, 2 ) dt
           USING (cat);

+-----+--------+--------+
| cat | subcat | amount |
+-----+--------+--------+
| A   |      1 |    123 |
| A   |      2 |    456 |
| B   |      1 |    555 |
| B   |      2 |      0 |
+-----+--------+--------+
4 rows in set (0.00 sec)

答案 5 :(得分:0)

这与您的解决方案有点类似,但UNION仅用于构建类别和子类别列表。然后该列表与另一个派生表连接,该表与UNION的右侧部分基本相同。这是:

SELECT s.cat, s.subcat, ISNULL(SUM(d.amount), 0)
FROM (
  SELECT cat, subcat FROM data
  UNION
  SELECT cat, subcat FROM config
) s
  LEFT JOIN (
    SELECT
      d.cat,
      subcat = ISNULL(c.subcat, d.subcat),
      d.amount
    FROM data d
      LEFT JOIN config c ON d.cat = c.cat
  ) d ON s.cat = d.cat AND s.subcat = d.subcat
GROUP BY s.cat, s.subcat