全外連接甲骨文

Question

我有以下數據來自不同的表中設置

Table1 
------- 
EMPID DEPID C1 C2 SUM 
--------------------------- 
100  200  2 3 111 
100  200  4 4 222 

Table2 
------- 
EMPID DEPID C1 C2 SUM 
--------------------------- 
100  200  4 4 333 
100  200  5 6 444 

結果我要找---

Table1 
------- 
EMPID DEPID T1.C1 T1.C2 T2.C1 T2.C2 T1.SUM T2.SUM 
-------------------------------------------------------------- 
100  200  2  3  NULL NULL  111  NULL 
100  200  4  4  4  4  222  333 
100  200  NULL NULL 5  6  NULL  444 

任何幫助大大appriciated。我使用了Full外部連接，但無法實現此功能。

Answer 1

你想要一個INNER JOIN在(emp_id, dep_id)與FULL OUTER JOIN在(c1, c2)。我認爲你將無法一步寫出這個連接條件。我提出了一個兩步查詢（一個FULL OUTER JOIN後跟一個篩選子查詢）。

SQL> WITH t1 AS (
    2 SELECT 100 emp_id, 200 dep_id, 2 c1, 3 c2, 111 sum FROM dual UNION ALL 
    3 SELECT 100 emp_id, 200 dep_id, 4 c1, 4 c2, 222 sum FROM dual 
    4 ), t2 AS (
    5 SELECT 100 emp_id, 200 dep_id, 4 c1, 4 c2, 333 sum FROM dual UNION ALL 
    6 SELECT 100 emp_id, 200 dep_id, 5 c1, 6 c2, 444 sum FROM dual UNION ALL 
    7 SELECT 100 emp_id, 300 dep_id, 7 c1, 8 c2, 555 sum FROM dual 
    8 ) 
    9 SELECT COALESCE(t1.emp_id, t2.emp_id) emp_id, 
10   COALESCE(t1.dep_id, t2.dep_id) dep_id, 
11   t1.c1, t1.c2, t2.c1, t2.c2, t1.sum, t2.sum 
12 FROM t1 
13 FULL OUTER JOIN t2 
14  ON t1.emp_id = t2.emp_id 
15  AND t1.dep_id = t2.dep_id 
16  AND t1.c1 = t2.c1 
17  AND t1.c2 = t2.c2 
18 WHERE (COALESCE(t1.emp_id, t2.emp_id), COALESCE(t1.dep_id, t2.dep_id)) 
19   IN (SELECT t1.emp_id, t1.dep_id 
20    FROM t1 
21    JOIN t2 ON t1.emp_id = t2.emp_id 
22      AND t1.dep_id = t2.dep_id) 
23 ORDER BY t1.c1; 

    EMP_ID  DEP_ID   C1   C2   C1   C2 SUM SUM 
---------- ---------- ---------- ---------- ---------- ---------- ---- ---- 
     100  200   2   3      111 
     100  200   4   4   4   4 222 333 
     100  200        5   6  444 

請注意，我在T2添加了一行，從你的例子來演示INNER JOIN。