子查询中的列外部连接 (ORA-01799)

Question

甲骨文 11g R2：

Table:

CREATE TABLE TABLE_1 
   (REC_ID NUMBER(10,0) NOT NULL,
    REV_ID NUMBER(10,0) NOT NULL ENABLE
   );
   
INSERT ALL
INTO TABLE_1 (REC_ID,REV_ID) 
VALUES (1,23)
INTO TABLE_1 (REC_ID,REV_ID) 
VALUES (1,36)
INTO TABLE_1 (REC_ID,REV_ID) 
VALUES (1,52)
INTO TABLE_1 (REC_ID,REV_ID) 
VALUES (2,19)
INTO TABLE_1 (REC_ID,REV_ID) 
VALUES (2,67)
INTO TABLE_1 (REC_ID,REV_ID) 
VALUES (2,98)
SELECT * FROM dual;

CREATE TABLE TABLE_2
   (REC_ID NUMBER(20,0) NOT NULL ENABLE
   ); 
     
INSERT ALL
INTO TABLE_2 (REC_ID) 
VALUES (1)
INTO TABLE_2 (REC_ID) 
VALUES (2)
SELECT * FROM dual;

我想加入 Table 2 和 Table 1 但只有 Table 1 REV_ID 是某个 [=33] 的最小值 REV_ID =].

+--------+--------+--------+
| REC_ID | REC_ID | REV_ID |
+--------+--------+--------+
|      1 |      1 |     23 |
|      2 |      2 |     19 |
+--------+--------+--------+

这个Select:

SELECT * from TABLE_2 T2
LEFT OUTER JOIN TABLE_1 T1 on T1.REC_ID = T2.REC_ID 
and T1.REV_ID = (SELECT MIN(REV_ID) from T1 where T1.REC_ID = T2.REC_ID)

适用于 MSSQL Server 2017 但会引发错误：

ORA-01799: a column may not be outer-joined to a subquery 在甲骨文中。

SQL Fiddle: LINK

问题：我如何重写查询以便连接在所有 oracle 版本中都有效？

Answer 1

您可以尝试以下查询 -

SELECT *
from TABLE_2 T2
LEFT OUTER JOIN (SELECT REC_ID, MIN(REV_ID)
                   FROM TABLE_1
                  GROUP BY REC_ID) T1 on T1.REC_ID = T2.REC_ID;

Link.

Answer 2

您可以将 CTE 与 row_number 一起使用，以分类具有最小 REV_ID 的行，并且仅对这些行进行外部连接。

优点是即使您想要 T1

中的一些其他属性，这种方法也能奏效

with t1_min as
(select REC_ID, REV_ID,
row_number() over (partition by REC_ID order by  REV_ID) as rn
from TABLE_1)
SELECT t2.rec_id t2_rec_id,t1.rec_id t1_rec_id,
t1.rev_id
from TABLE_2 T2
LEFT OUTER JOIN t1_min T1 on T1.REC_ID = T2.REC_ID 
and t1.rn = 1

 T2_REC_ID  T1_REC_ID     REV_ID
---------- ---------- ----------
         1          1         23
         2          2         19

子查询中的列外部连接 (ORA-01799)

Column outer joined in subquery (ORA-01799)

oracle

subquery

left-join