Question

希望我能正确解释一下。我有一个行订单表（每个行顺序包括项目数量和价格，还有其他字段，但我把它们排除了。）

表'orderitems'：

orderid | quantity | price
1       | 1        | 1.5000
1       | 2        | 3.22
2       | 1        | 9.99
3       | 4        | 0.44
3       | 2        | 15.99

因此，为了获得订单总数，我会运行

SELECT     SUM(Quantity * price) AS total
FROM          OrderItems
GROUP BY OrderID

但是，我想得到1美元以下的总订单数（仅提供一个计数）。

我希望能够定义范围的最终结果：低于1美元，1美元 - 3美元，3-5美元，5-10美元，10-15美元，15美元等等;

和我的数据看起来如此（希望如此）：

tunder1 | t1to3 | t3to5 | t5to10 | etc
10      | 500   | 123   | 5633   |

这样我就可以在我们的电子商务网站上呈现客户订单的饼图细分。现在我可以运行单独的SQL查询来获得这个，但我想知道最有效的“单个SQL查询”是什么。我正在使用MS SQL Server。

目前我可以像这样运行一个查询，总计不到1美元：

SELECT     COUNT(total) AS tunder1
FROM         (SELECT     SUM(Quantity * price) AS total
                       FROM          OrderItems
                       GROUP BY OrderID) AS a
WHERE     (total < 1)

如何优化此功能？提前谢谢！

Answer 1

select 
  count(case when total < 1 then 1 end) tunder1,
  count(case when total >= 1 and total < 3 then 1 end) t1to3,
  count(case when total >= 3 and total < 5 then 1 end) t3to5,
  ...
from
(
  select sum(quantity * price) as total
  from orderitems group by orderid
);

Answer 2

您需要使用HAVING来过滤分组值。

Answer 3

试试这个：

DECLARE @YourTable table (OrderID int, Quantity int, Price decimal)
INSERT INTO @YourTable VALUES (1,1,1.5000)
INSERT INTO @YourTable VALUES (1,2,3.22)
INSERT INTO @YourTable VALUES (2,1,9.99)
INSERT INTO @YourTable VALUES (3,4,0.44)
INSERT INTO @YourTable VALUES (3,2,15.99)

SELECT
    SUM(CASE WHEN TotalCost<1 THEN 1 ELSE 0 END) AS tunder1
        ,SUM(CASE WHEN TotalCost>=1 AND TotalCost<3 THEN 1 ELSE 0 END) AS t1to3
        ,SUM(CASE WHEN TotalCost>=3 AND TotalCost<5 THEN 1 ELSE 0 END) AS t3to5
        ,SUM(CASE WHEN TotalCost>=5 THEN 1 ELSE 0 END) AS t5andup
    FROM (SELECT
              SUM(quantity * price) AS TotalCost
              FROM @YourTable
              GROUP BY OrderID
         ) dt

输出：

tunder1     t1to3       t3to5       t5andup
----------- ----------- ----------- -----------
0           0           0           3

(1 row(s) affected)

Answer 4

WITH    orders (orderid, quantity, price) AS
        (
        SELECT  1, 1, 1.5
        UNION ALL
        SELECT  1, 2, 3.22
        UNION ALL
        SELECT  2, 1, 9.99
        UNION ALL
        SELECT  3, 4, 0.44
        UNION ALL
        SELECT  4, 2, 15.99
        ),
        ranges (bound) AS
        (
        SELECT  1
        UNION ALL
        SELECT  3
        UNION ALL
        SELECT  5
        UNION ALL
        SELECT  10
        UNION ALL
        SELECT  15
        ),
        rr AS
        (
        SELECT  bound, ROW_NUMBER() OVER (ORDER BY bound) AS rn
        FROM    ranges
        ),
        r AS
        (
        SELECT  COALESCE(rf.rn, 0) AS rn, COALESCE(rf.bound, 0) AS f,
                rt.bound AS t
        FROM    rr rf
        FULL JOIN
                rr rt
        ON      rt.rn = rf.rn + 1
        )
SELECT  rn, f, t, COUNT(*) AS cnt
FROM    r
JOIN    (
        SELECT  SUM(quantity * price) AS total
        FROM    orders
        GROUP BY
                orderid
        ) o
ON      total >= f
        AND total < COALESCE(t, 10000000)
GROUP BY
        rn, t, f

输出：

rn      f       t       cnt
1       1       3       1
3       5       10      2
5       15      NULL    1

，即从1到$1的{{1}}订单，从$3到$5的2个订单，$10订单超过{{ 1}}。

生成按订单总计分组的订单统计信息

4 个答案: