Question

请帮助以下Oracle SQL查询：

尝试了几种方法，但未获得预期的结果。

数据集：

ORDER_NO    ITEM CODE
1234      999999    777
1234      999999    111
1234      999999    777
1234      999999    111

预期结果：

ORDER_NO    ITEM     CODE
1234      999999      777
                      111

Answer 1

您可以尝试通过dcast(aggregate_comments_data, event.post.id ~ event.is_comment_to_post, fun = length)中的ROW_NUMBER窗口函数来创建行号，然后使用CTE来创建行号。

CASE WHEN

查询1 ：

CREATE TABLE T(
   ORDER_NO INT,
   ITEM INT,
   CODE INT
);


INSERT INTO T VALUES (1234,999999,777);
INSERT INTO T VALUES (1234,999999,111);
INSERT INTO T VALUES (1234,999999,777);
INSERT INTO T VALUES (1234,999999,111);

Results ：

with cteRn as (
  SELECT t1.*,ROW_NUMBER() OVER (PARTITION BY ORDER_NO,ITEM,CODE order by ORDER_NO) rn 
  FROM T t1
), cteGrp as (
  SELECT
       t1.*,ROW_NUMBER() OVER (PARTITION BY ORDER_NO,ITEM ORDER BY CODE desc) grp
  FROM cteRn t1
  WHERE rn = 1
)

SELECT  
     (CASE WHEN grp = 1 then ORDER_NO end) ORDER_NO,
     (CASE WHEN grp = 1 then ITEM end)  ITEM,
     CODE 
FROM cteGrp

Answer 2

当您为SQL Developer标记了此标记（在这种情况下可以被认为是应用程序/表示层）时，您可以使用break ... nodup：

clear breaks
break on order_no nodup on item nodup

with your_table (order_no, item, code) as (
  select 1234, 999999, 777 from dual
  union all select 1234, 999999, 111 from dual
  union all select 1234, 999999, 777 from dual
  union all select 1234, 999999, 111 from dual
)
select * from your_table;

  ORDER_NO       ITEM       CODE
---------- ---------- ----------
      1234     999999        777
                             111
                             777
                             111

具有多个订单和商品：

with your_table (order_no, item, code) as (
  select 1234, 999999, 777 from dual
  union all select 1234, 999999, 111 from dual
  union all select 1234, 999999, 777 from dual
  union all select 1234, 999999, 111 from dual
  union all select 1235, 999999, 111 from dual
  union all select 1236, 999999, 111 from dual
  union all select 1236, 999998, 111 from dual
  union all select 1236, 999998, 111 from dual
)
select * from your_table;

  ORDER_NO       ITEM       CODE
---------- ---------- ----------
      1234     999999        777
                             111
                             777
                             111
      1235     999999        111
      1236     999999        111
      1236     999998        111
                             111

Oracle SQL-将重复值设置为null

2 个答案: