与えられた条件を満たす多くの行のうちの1行を除くすべての行を更新するにはどうすればよいですか？

テーブルの更新中は行の順序を気にしないので、 MINを使用するだけで済みます。 およびGROUPBY 。

更新 colAでグループ化する必要があります およびcolC 。

たとえば、

セットアップ

SQL> CREATE TABLE t
  2    (
  3      COlA VARCHAR2(12),
  4      COLB VARCHAR2(9),
  5      COLC VARCHAR2(5),
  6      COLD VARCHAR2(5),
  7      COLE VARCHAR2(1)
  8    );

Table created.

SQL> INSERT ALL
  2      INTO t (COlA, COLB, COLC, COLD, COLE)
  3           VALUES ('Equipment SI', 'ADD INFO', 'MERGE', 'Notes', 'Y')
  4      INTO t (COlA, COLB, COLC, COLD, COLE)
  5           VALUES ('Equipment SI', 'Active', 'MERGE', 'Notes', 'Y')
  6      INTO t (COlA, COLB, COLC, COLD, COLE)
  7           VALUES ('Equipment SI', 'ORIGINAL', 'MERGE', 'Notes', 'Y')
  8      INTO t (COlA, COLB, COLC, COLD, COLE)
  9           VALUES ('Fastening', 'ADD INFO', 'MERGE', 'Notes', 'Y')
 10      INTO t (COlA, COLB, COLC, COLD, COLE)
 11           VALUES ('Fastening', 'Active', 'MERGE', 'Notes', 'Y')
 12      INTO t (COlA, COLB, COLC, COLD, COLE)
 13           VALUES ('Electonics', 'ADD INFO', 'MERGE', 'Notes', 'Y')
 14      INTO t (COlA, COLB, COLC, COLD, COLE)
 15           VALUES ('Electonics', 'Active O', 'MERGE', 'Notes', 'Y')
 16      INTO t (COlA, COLB, COLC, COLD, COLE)
 17           VALUES ('Electonics', 'ORIGINAL', 'MERGE', 'Notes', 'Y')
 18      INTO t (COlA, COLB, COLC, COLD, COLE)
 19           VALUES ('Electonics', 'Nominated', 'MERGE', 'Notes', 'Y')
 20      INTO t (COlA, COLB, COLC, COLD, COLE)
 21           VALUES ('Fiber', 'ADD INFO', 'MULTI', 'Notes', 'Y')
 22      INTO t (COlA, COLB, COLC, COLD, COLE)
 23           VALUES ('Fiber', 'ADD INFO', 'KILO', 'Notes', 'Y')
 24  SELECT * FROM dual;

11 rows created.

SQL> COMMIT;

Commit complete.

テーブルデータ

SQL> SELECT * FROM t;

COLA         COLB      COLC  COLD  C
------------ --------- ----- ----- -
Equipment SI ADD INFO  MERGE Notes Y
Equipment SI Active    MERGE Notes Y
Equipment SI ORIGINAL  MERGE Notes Y
Fastening    ADD INFO  MERGE Notes Y
Fastening    Active    MERGE Notes Y
Electonics   ADD INFO  MERGE Notes Y
Electonics   Active O  MERGE Notes Y
Electonics   ORIGINAL  MERGE Notes Y
Electonics   Nominated MERGE Notes Y
Fiber        ADD INFO  MULTI Notes Y
Fiber        ADD INFO  KILO  Notes Y

11 rows selected.

更新ステートメント

SQL> UPDATE t
  2  SET colE         = 'N'
  3  WHERE ROWID NOT IN
  4    ( SELECT MIN(rowid) FROM t GROUP BY colA, colC
  5    );

6 rows updated.

確認しましょう

SQL> SELECT * FROM t;

COLA         COLB      COLC  COLD  C
------------ --------- ----- ----- -
Equipment SI ADD INFO  MERGE Notes Y
Equipment SI Active    MERGE Notes N
Equipment SI ORIGINAL  MERGE Notes N
Fastening    ADD INFO  MERGE Notes Y
Fastening    Active    MERGE Notes N
Electonics   ADD INFO  MERGE Notes Y
Electonics   Active O  MERGE Notes N
Electonics   ORIGINAL  MERGE Notes N
Electonics   Nominated MERGE Notes N
Fiber        ADD INFO  MULTI Notes Y
Fiber        ADD INFO  KILO  Notes Y

11 rows selected.

SQL>