SQL合并行而不是UNION ALL 查询结果

如何解决SQL合并行而不是UNION ALL 查询结果

我正在做UNION ALL来获得结果，如下表所示。这种方法导致不必要的行。 DESK，SEGMENT和SUPERVISOR这三列是独立的，没有关系。

代码

SELECT ID,DESK,'' as SEGMENT,'' as SUPERVISOR FROM myTable1 
UNION ALL 
SELECT ID,'' AS DESK,SEGMENT,'' as SUPERVISOR FROM myTable2 
UNION ALL 
SELECT ID,SUPERVISOR FROM myTable3 

结果：

+------+------------+---------+------------+
| ID   | DESK       | SEGMENT | SUPERVISOR | TOTAL ENTRIES
+------+------------+---------+------------+
| 4782 | OIL & GAS  |         |            |  23
+------+------------+---------+------------+
| 4782 | AUTOMOTIVE |         |            |  23
+------+------------+---------+------------+
| 4782 |            | GLOBAL  |            |  23
+------+------------+---------+------------+
| 4782 |            |         | DANIEL     |  23
+------+------------+---------+------------+
| 4782 |            |         | JAMES      |  23
+------+------------+---------+------------+

如何查询以获得以下结果？

预期结果：

+------+------------+---------+------------+
| ID   | DESK       | SEGMENT | SUPERVISOR | TOTAL ENTRIES
+------+------------+---------+------------+
| 4782 | OIL & GAS  | GLOBAL  | DANIEL     |  23
+------+------------+---------+------------+
| 4782 | AUTOMOTIVE |         | JAMES      |  23
+------+------------+---------+------------+

解决方法

对于这三个表，可以将ROW_NUMBER()分析函数与ID一起按FULL OUTER JOIN列进行分区：

SELECT NVL(NVL(t2.ID,t3.ID),t1.ID) AS ID,desk,segment,supervisor 
  FROM ( SELECT t1.*,ROW_NUMBER() OVER (PARTITION BY ID ORDER BY 0) AS rn FROM myTable1 t1 ) t1
  FULL JOIN ( SELECT t2.*,ROW_NUMBER() OVER (PARTITION BY ID ORDER BY 0) AS rn FROM myTable2 t2 ) t2
    ON t2.ID = t1.ID AND t2.rn = t1.rn
  FULL JOIN ( SELECT t3.*,ROW_NUMBER() OVER (PARTITION BY ID ORDER BY 0) AS rn FROM myTable3 t3 ) t3
    ON t3.ID = t1.ID AND t3.rn = t1.rn;


ID   DESK        SEGMENT  SUPERVISOR
---- ----------  -------  ----------
4782 AUTOMOTIVE  GLOBAL   JAMES
4782 OIL & GAS            DANIEL  

Demo

P.S：我离开了ORDER BY 0，因为ORDER BY必须使用ROW_NUMBER()选项，您可以用合适的列或标识符替换零。

,

您可以尝试以下方法：

SELECT table1.ID,table1.DESK,table2.SEGMENT,(select SUPERVISOR from (select SUPERVISOR,ROWNUM AS RN FROM table3) WHERE RN = 1) SUPERVISOR
FROM table1 JOIN table2 on table1.ID = table2.ID
WHERE table1.DESK = 'OIL & GAS'
UNION ALL
SELECT table1.ID,null SEGMENT,ROWNUM AS RN FROM table3) WHERE RN = 2) SUPERVISOR
FROM table1 JOIN table2 on table1.ID = table2.ID
WHERE table1.DESK = 'AUTOMOTIVE'

https://dbfiddle.uk/?rdbms=oracle_11.2&fiddle=c5594bb1d99579611d2669f6bab675a2

,

您可以尝试以下查询。我不知道23的来源，因此我没有将其计入查询中，但是如果它是三个表之一中的一列，则可以使用类似的逻辑将其添加到结果中。

查询

WITH
    table1 (id,desk)
    AS
        (SELECT 4782,'OIL & GAS' FROM DUAL
         UNION ALL
         SELECT 4782,'AUTOMOTIVE' FROM DUAL),table2 (id,segment) AS (SELECT 4782,'GLOBAL' FROM DUAL),table3 (id,supervisor)
    AS
        (SELECT 4782,'DANIEL' FROM DUAL
         UNION ALL
         SELECT 4782,'JAMES' FROM DUAL)
SELECT *
  FROM (SELECT t1.id,CASE WHEN t1.desk = LAG (t1.desk) OVER (ORDER BY t1.desk) THEN NULL ELSE t1.desk END
                   AS desk,CASE
                   WHEN t2.segment = LAG (t2.segment) OVER (ORDER BY t2.segment) THEN NULL
                   ELSE t2.segment
               END
                   AS segment,CASE
                   WHEN t3.supervisor = LAG (t3.supervisor) OVER (ORDER BY t3.supervisor) THEN NULL
                   ELSE t3.supervisor
               END
                   AS supervisor
          FROM table1 t1,table2 t2,table3 t3
         WHERE t1.id = t2.id AND t1.id = t3.id)
 WHERE desk IS NOT NULL OR segment IS NOT NULL OR supervisor IS NOT NULL;

结果

     ID          DESK    SEGMENT    SUPERVISOR
_______ _____________ __________ _____________
   4782 AUTOMOTIVE    GLOBAL     DANIEL
   4782 OIL & GAS                JAMES