如何使用 SQL 找出只在一家商店购物的客户

Question

我想查看特定时期内只在一家特定商店购物的顾客数量，所以我写了如下 SQL：

SELECT COUNT (DISTINCT CARD_NUMBER)
FROM <TRANSACTION TABLE>
WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
AND STORE_NUMBER = 1234;

如果这些客户（持卡人）在其他连锁店购物怎么办？

我无法使用 AND CARD_NUMBER NOT IN… 因为我们的店太多了。 任何可以在这里使用的语法来解决这个问题？

Answer 1

如果所有交易都在一个商店中，那么 MIN 和 MAX 是相同的：

SELECT COUNT(*)
FROM
 ( 
   SELECT CARD_NUMBER
   FROM <TRANSACTION TABLE>
   WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
   GROUP BY CARD_NUMBER
   HAVING MIN(STORE_NUMBER) = 1234  -- shopped in this store
       AND MAX(STORE_NUMBER) = 1234  -- but no other store 
 ) dt;

Answer 2

如果我理解您的问题，您想知道在给定时间段内有多少客户仅在商店 1234 购物。

我认为这样做：

SELECT COUNT (DISTINCT CARD_NUMBER)
  FROM <TABLE>
 WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
   AND STORE_NUMBER = 1234
   AND CARD_NUMBER NOT IN (SELECT DISTINCT CARD_NUMBER
                             FROM <TABLE>
                            WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE)
                                           AND ‘XXXX-XX-XX’(DATE)
                              AND STORE_NUMBER <> 1234);

子选择会为您提供在该时间段内在其他地方购物的卡号列表。因此，您的意思是，“向我显示商店 1234 的给定日期的所有卡号，其中该号码未出现在其他商店使用的卡号列表中。”

希望有帮助

Answer 3

在您的 NOT IN 子句中添加另一个选择语句 ... AND NOT IN (SELECT DISTINCT STORE_NUMBER FROM FOO WHERE STORE_NUMBER != 1234)

Answer 4

正如我在评论中提到的，许多数据库优化器会将NOT IN (...) 重写为NOT EXISTS。在您的情况下，NOT EXISTS 和 LEFT OUTER JOIN 都可以使用...

使用NOT EXISTS：

SELECT COUNT (DISTINCT CARD_NUMBER)
FROM <TRANSACTION TABLE> T
WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
AND NOT EXISTS (
  SELECT 1
  FROM <TRANSACTION TABLE> T
  WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
  AND STORE_NUMBER <> 1234
)
AND STORE_NUMBER = 1234;

使用LEFT OUTER JOIN：

SELECT COUNT (DISTINCT CARD_NUMBER)
FROM <TRANSACTION TABLE> T
LEFT OUTER JOIN  <TRANSACTION TABLE> CHECK
    ON  T.CARD_NUMBER = CHECK.CARD_NUMBER
    AND CHECK.DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
    AND STORE_NUMBER <> 1234
WHERE T.DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
AND T.STORE_NUMBER = 1234
AND CHECK.CARD_NUMBER IS NULL;

Answer 5

With card_list as (
-- get the custs that shopped 1234
select CARD_NUMBER
FROM <TRANSACTION TABLE>
WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
AND STORE_NUMBER = 1234

EXCEPT
-- Remove from the above list those that shopped other stores

-- get the custs that shopped all other stores
select CARD_NUMBER
FROM <TRANSACTION TABLE>
WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
AND STORE_NUMBER <> 1234
)

-- get the counts, this is already a unique list so no distinct needed.
select count(CARD_NUMBER) from card_list;'

Answer 6

SELECT COUNT(*)
FROM
 ( 
   SELECT CARD_NUMBER
    FROM <TRANSACTION TABLE>
    WHERE DATE BETWEEN ‘XXXX-XX-XX’(DATE) AND ‘XXXX-XX-XX’(DATE)
    AND STORE_NUMBER = '1234'
    GROUP BY CARD_NUMBER
    HAVING COUNT(CARD_NUMBER) = 1
  ) dt;