Načíst záznamy z konkrétního sloupce v oracle

Nastavení 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;

Dotaz :

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;

Výstup :

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

Pokud chcete získat zápasy, můžete použít sbírku:

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

Dotaz :

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;

nebo (protože si nejsem jistý MULTISET je v 10 g):

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;

Výstup

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