Извличане на записи от конкретна колона в Oracle

Настройка на Oracle :

CREATE TABLE table_name ( S_NO, id, Pid ) AS
SELECT 1, 123, 'PAQ123' FROM DUAL UNION ALL
SELECT 2, 433, 'WSD3FF' FROM DUAL UNION ALL  
SELECT 3, 565, 'PAS45E' FROM DUAL UNION ALL
SELECT 4, 123, 'PAQ123X' FROM DUAL UNION ALL
SELECT 5, 433, 'WSD3FFY' FROM DUAL UNION ALL
SELECT 6, 123, 'PAQ123Z' FROM DUAL;

Запитване :

SELECT *
FROM   (
  SELECT t.*,
         ( SELECT COUNT(*)
           FROM   table_name x
           WHERE  t.id = x.id
           AND    LENGTH( t.Pid ) < LENGTH( x.pid )
           AND    INSTR( x.Pid, t.Pid ) = 1 ) AS num_matches
  FROM   Table_name t
)
WHERE num_matches > 0;

Изход :

      S_NO         ID PID     NUM_MATCHES
---------- ---------- ------- -----------
         1        123 PAQ123            2 
         2        433 WSD3FF            1 

Ако искате да получите съвпаденията, можете да използвате колекция:

CREATE TYPE stringlist AS TABLE OF VARCHAR2(100);
/

Запитване :

SELECT *
FROM   (
  SELECT t.*,
         CAST(
           MULTISET(
             SELECT PID
             FROM   table_name x
             WHERE  t.id = x.id
             AND    LENGTH( t.Pid ) < LENGTH( x.pid )
             AND    INSTR( x.Pid, t.Pid ) = 1
           )
           AS stringlist
         ) AS matches
  FROM   Table_name t
)
WHERE matches IS NOT EMPTY;

или (тъй като не съм сигурен MULTISET е в 10g):

SELECT *
FROM   (
  SELECT t.*,
         CAST(
           ( 
             SELECT COLLECT( PID )
             FROM   table_name x
             WHERE  t.id = x.id
             AND    LENGTH( t.Pid ) < LENGTH( x.pid )
             AND    INSTR( x.Pid, t.Pid ) = 1
           )
           AS stringlist
         ) AS matches
  FROM   Table_name t
)
WHERE matches IS NOT EMPTY;

Изход

      S_NO         ID PID     MATCHES 
---------- ---------- ------- ------------------------------------
         1        123 PAQ123  TEST.STRINGLIST('PAQ123X','PAQ123Z')
         2        433 WSD3FF  TEST.STRINGLIST('WSD3FFY')