计算 SQL 服务器中的条目和数据透视表

Question

我有一个关于枢轴 tables 和总结的问题

源select语句输出如下结构

Customer|ProductID
A       |1
A       |4
B       |3
C       |2
D       |3
D       |3
D       |4

我想将其转换为具有以下结构的 table：

Customer|Count|1|2|3|4
A       |2    |1|0|0|1
B       |1    |0|0|1|0
C       |1    |0|1|0|0
D       |3    |1|0|1|1

"Count"应该是客户购买的产品数量，但我无法让它工作:(

这里是 SQL:

SELECT customerId, CustomerNo, [1], [2], [3], [4] FROM

(SELECT id AS customerId, 
CustomerNo,
CASE ProductType
WHEN 1 THEN 1 /* Games */
WHEN 2 THEN 2 /* Cards */
WHEN 4 THEN 3 /* Gadgets */
WHEN 5 THEN 3 /* Accessories */
WHEN 6 THEN 4 /* Smartsphone acc. */
ELSE 255
END AS Products,
FROM
ProductSales
) AS SourceTable 

PIVOT ( 
COUNT(Products)
FOR Products IN ([1], [2], [3], [4])
) AS PivotTable

这工作正常，但我需要在第一个 SELECT 语句中添加某种 COUNT 以计算每个客户拥有的记录数。

任何帮助将不胜感激。提前致谢:)

/汉斯

Answer 1

尝试使用条件聚合而不是数据透视表：

SELECT t.customerid,
       COUNT(*) as cnt,
       MAX(CASE WHEN t.productid = 1 THEN 1 ELSE 0 END) as first,
       MAX(CASE WHEN t.productid = 2 THEN 1 ELSE 0 END) as second,
       MAX(CASE WHEN t.productid = 3 THEN 1 ELSE 0 END) as third
FROM YourTable t
GROUP BY t.customerid

Answer 2

根据您当前的查询，使用 PIVOT 没有问题。
只需将以下列添加到 SELECT.

[1]+[2]+[3]+[4] as [Count]

演示

create table t (customer char(1),ProductID int)
insert into t values ('A',1),('A',4),('B',3),('C',2),('D',3),('D',3),('D',4)

select      customer
           ,[1]+[2]+[3]+[4] as [Count]
           ,[1],[2],[3],[4]

from        t pivot (count(ProductID) for ProductID in ([1],[2],[3],[4])) t

+----------+-------+---+---+---+---+
| customer | Count | 1 | 2 | 3 | 4 |
+----------+-------+---+---+---+---+
| A        | 2     | 1 | 0 | 0 | 1 |
+----------+-------+---+---+---+---+
| B        | 1     | 0 | 0 | 1 | 0 |
+----------+-------+---+---+---+---+
| C        | 1     | 0 | 1 | 0 | 0 |
+----------+-------+---+---+---+---+
| D        | 3     | 0 | 0 | 2 | 1 |
+----------+-------+---+---+---+---+

计算 SQL 服务器中的条目和数据透视表

Counting entries and pivot tables in SQL Server

sql

sql-server

pivot