Protože se při aktualizaci tabulky nestaráte o řazení řádků, můžete jednoduše použít MIN a GROUP BY .
Aktualizovat Musíte seskupit podle colA
a colC
.
Například,
Nastavení
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.
Data tabulky
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.
Aktualizovat prohlášení
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.
Pojďme to zkontrolovat
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>