Oracle/SQL-多表联接逻辑-不确定如何表达它

我要做的是找到所有在前一天购买了

Series X

或

Series a

小部件的客户，只要他们是第一次从该小部件购买小部件。如果他们购买了多个符合条件的小部件

Series X

，我应该只会得到一条记录。希望这是有意义的，下面是数据

[customers]
c_id     cp_id
--------------
1        cp1
2        cp2
3        cp3
4        cp4
5        cp5
6        cp6
7        cp7
8        cp8
9        cp9
10       cp10

[widget_orders - c_id maps to c_id in customers]
c_id    w_sku   o_date
----------------------
1       w1      2012-10-10
2       w1      2012-10-10
2       w2      2012-10-10
3       w1      2012-10-10
3       w2      2012-10-10
4       w1      2012-10-10
4       w2      2012-10-10
5       w1      2012-10-10
5       w2      2012-10-10
6       w1      2012-10-10
6       w2      2012-10-10
7       w2      2012-10-10
8       w1      2012-10-10
9       w3      2012-10-10

[widgets - w_sku maps to w_sku in widget_orders]
w_sku   w_series
------------------
w1      Series A
w2      Series X
w3      Series C

[customer_data - c_id maps to c_id in customers]
cp_id   seriesA_fPurch  seriesX_fPurch
--------------------------------------
cp3     
cp4     2012-09-15
cp5                     2012-09-15
cp6     2012-09-15      2012-09-15
cp7                     2012-09-15  
cp8     2012-09-15

下面是我想要得到的数据，忽略（）

以下人员未显示在结果中

cp6 - they had previously bought both series
cp7 - bought a series x, but had in the past
cp8 - bought a series a, but had in the past
cp9 - bought a widget in neither series
cp10 - didnt buy anything

希望所有这些都是有意义的，有人能在这里帮助我

因此，总结一下逻辑，也许在这里更清楚地定义一下，我将以一种循序渐进的方式描述需要发生的事情

1) Find all customers who have no matching records in the customer_data table
2) Find all customers who have a null value in either *purch column in the customer_data table
3) Combine these results together
4) Take the results and find the customers who made a purchase yesterday
5) Take the results and find the customers who purchased Series A or Series X
6) Take the results and do the following
    6a) If the purchase was Series A and they have a value for series A purch already drop them from results
    6b) If the purchase was Series X and they have a value for series X purch already drop them from results
7) Take the results and remove duplicate records based on the cp_id - Series X takes presedence over Series A

---

我不确定我是否完全理解您的要求，但请尝试：

SELECT cp_id, w_series
FROM (
SELECT rank() over (partition BY wo."c_id" ORDER BY decode(w."w_series",'Series X',1,'Series A',2)) rank,
       wo."c_id" c_id,
       c."cp_id" cp_id,
       w."w_series" w_series
FROM widget_orders wo JOIN widgets w ON wo."w_sku"=w."w_sku"
  JOIN customers c on c."c_id"=wo."c_id"
LEFT OUTER JOIN customer_data cd ON c."cp_id" = cd."cp_id"
WHERE  w."w_series" IN ('Series A', 'Series X')
  AND  trunc(wo."o_date") = trunc(sysdate)-1
  AND ( (cd."seriesA_fPurch" IS NULL AND w."w_series"='Series A')
     OR (cd."seriesX_fPurch" IS NULL AND w."w_series"='Series X'))
  )
WHERE rank = 1

他是一把小提琴

说明：
根据步骤式编号-
1） +2）是在

左外连接

+

cd中完成的。“seriesA_fpourch”为空

条件+

cd。“seriex_fpourch”为空

条件，因为它也会找到那些没有记录的人，并将其置为空。
3） 显而易见……
4）

trunc（wo.“o_日期”）=trunc（sysdate）-1

condition
5）

w（'series A'、'series X'）中的“w_series”

6）

（cd.“seriesA_fpourch”为空，w.“w_series”='series A'）
或（cd.“seriexx_fpourch”为空，w.“w_series”='series X'）

条件

---

7） 通过给记录赋予一个等级，并根据小提琴给出等级=1的条件，看起来这是可行的，但我确实有点说错了。customers表连接到另一个字段上的customer_数据表。您的查询似乎没有利用customer表，但最终需要这样做。我现在正在更新这个问题。@dscl，我认为你的句子应该以“感谢你努力理解我的场景，创建表格，并用数据填充它，使之成为废话…”开头。只有通过这份出色的工作，A.B.Cade才能获得+1。@danihp你绝对正确！感谢A.B.Cade关注我的问题并解决它。如果你能再看一眼，我当然会很感激。如果你不能，我理解并且仍然感激你已经付出的努力。@dscl，我更新了我的答案，在

客户

表中添加了另一个联接，并将

左外部联接

条件更改为映射到客户。我补充的另一件事是只提及银行A.B.Cade的“昨天”日期的条件-你不知道我有多感激它！

SELECT cp_id, w_series
FROM (
SELECT rank() over (partition BY wo."c_id" ORDER BY decode(w."w_series",'Series X',1,'Series A',2)) rank,
       wo."c_id" c_id,
       c."cp_id" cp_id,
       w."w_series" w_series
FROM widget_orders wo JOIN widgets w ON wo."w_sku"=w."w_sku"
  JOIN customers c on c."c_id"=wo."c_id"
LEFT OUTER JOIN customer_data cd ON c."cp_id" = cd."cp_id"
WHERE  w."w_series" IN ('Series A', 'Series X')
  AND  trunc(wo."o_date") = trunc(sysdate)-1
  AND ( (cd."seriesA_fPurch" IS NULL AND w."w_series"='Series A')
     OR (cd."seriesX_fPurch" IS NULL AND w."w_series"='Series X'))
  )
WHERE rank = 1