Oracle 23c

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ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
CREATE TABLE A (
  PC_ID INT,
  EDI_ID INT
);
CREATE TABLE B (
  ID INT,
  KEY VARCHAR(255),
  VALUE VARCHAR(255)
);
INSERT INTO A (PC_ID, EDI_ID) VALUES (100,10), (100,12), (100,13), (101,20), (102, 30), (103,40), (12, 50),(324, 120);
8 rows affected

INSERT INTO B (ID, KEY, VALUE) VALUES
(10, 'X', 'some'),
(12, 'Y', 'something'),
(13, 'Z', 'thing'),
(20, 'Z', 'thing'),
(30, 'Z', 'thing'),
(40, 'Z', 'thing'),
(50, 'Z', 'thing'),
(120, 'NO', 'nothing to see');
8 rows affected

SELECT PC_ID 
FROM A a
       left join B b 
      on a.EDI_ID = b.ID
WHERE b.key='X' AND b.value='some'
AND a.PC_ID in (
SELECT PC_ID  
FROM A a
left join B b
on a.EDI_ID = b.ID
where b.key='Y' AND b.value='something'
)
AND a.PC_ID in (
SELECT PC_ID  
FROM A a 
left join B b 
on a.EDI_ID = b.ID
where b.key='Z' AND b.value='thing'
)


PC_ID


100


SELECT a.pc_id
FROM   a
       INNER JOIN b
       ON a.edi_id = b.id
WHERE  (b.key, b.value) IN (
         ('X', 'some'), ('Y', 'something'), ('Z', 'thing')
       )
GROUP BY a.pc_id
HAVING COUNT(DISTINCT b.key) = 3


PC_ID


100


SELECT a.pc_id
FROM   a
       INNER JOIN b
       ON a.edi_id = b.id
WHERE  (b.key, b.value) IN (
         ('X', 'some'), ('Y', 'something'), ('Z', 'thing')
       )
GROUP BY a.pc_id
HAVING MAX(CASE b.key WHEN 'X' THEN 1 END) = 1
AND    MAX(CASE b.key WHEN 'Y' THEN 1 END) = 1
AND    MAX(CASE b.key WHEN 'Z' THEN 1 END) = 1


PC_ID


100


SELECT pc_id
FROM   (
  SELECT a.pc_id,
         b.key
  FROM   a
         INNER JOIN b
         ON a.edi_id = b.id
  WHERE  (b.key, b.value) IN (
           ('X', 'some'), ('Y', 'something'), ('Z', 'thing')
         )
)
MATCH_RECOGNIZE(
  PARTITION BY pc_id
  ORDER BY key
  PATTERN (x+ y+ z+)
  DEFINE x AS key = 'X',
         y AS key = 'Y',
         z AS key = 'Z'
)


PC_ID


100