Brug en hierarkisk forespørgsel og filter til kun at få bladknuderne.
Oracle-opsætning :
CREATE TABLE table_name ( bom_code, rm_code, qty ) AS
SELECT 'A', 'B', 1 FROM DUAL UNION ALL
SELECT 'A', 'C', 2 FROM DUAL UNION ALL
SELECT 'A', 'D', 5 FROM DUAL UNION ALL
SELECT 'A', 'E', 3 FROM DUAL UNION ALL
SELECT 'A', 'F', 8 FROM DUAL UNION ALL
SELECT 'D', 'G', 2 FROM DUAL UNION ALL
SELECT 'D', 'H', 1 FROM DUAL UNION ALL
SELECT 'D', 'I', 1 FROM DUAL UNION ALL
SELECT 'D', 'J', 1 FROM DUAL UNION ALL
SELECT 'F', 'K', 1 FROM DUAL UNION ALL
SELECT 'F', 'L', 1 FROM DUAL UNION ALL
SELECT 'G', 'Z', 1 FROM DUAL UNION ALL
SELECT 'G', 'AA', 3 FROM DUAL UNION ALL
SELECT 'I', 'M', 4 FROM DUAL UNION ALL
SELECT 'I', 'N', 9 FROM DUAL UNION ALL
SELECT 'I', 'O', 7 FROM DUAL UNION ALL
SELECT 'N', 'P', 6 FROM DUAL UNION ALL
SELECT 'N', 'Q', 12 FROM DUAL UNION ALL
SELECT 'N', 'R', 4 FROM DUAL UNION ALL
SELECT 'N', 'S', 9 FROM DUAL UNION ALL
SELECT 'S', 'T', 3 FROM DUAL UNION ALL
SELECT 'S', 'U', 2 FROM DUAL UNION ALL
SELECT 'T', 'V', 1 FROM DUAL UNION ALL
SELECT 'T', 'W', 3 FROM DUAL UNION ALL
SELECT 'U', 'X', 5 FROM DUAL UNION ALL
SELECT 'U', 'Y', 8 FROM DUAL;
Forespørgsel :
SELECT t.*,
SYS_CONNECT_BY_PATH( BOM_CODE, '-' ) || '-' || RM_CODE AS path,
LEVEL
FROM table_name t
WHERE CONNECT_BY_ISLEAF = 1
START WITH bom_code = 'A'
CONNECT BY PRIOR rm_code = bom_code;
Output :
Forespørgsel 2 :
Hvis du vil have den samlede mængde langs stien, skal du bruge en korreleret underforespørgsel til at krydse hierarkiet i den modsatte retning:
SELECT t.*,
SYS_CONNECT_BY_PATH( BOM_CODE, '-' ) || '-' || RM_CODE AS path,
LEVEL,
( SELECT SUM( qty )
FROM table_name s
START WITH t.rm_code = s.rm_code
CONNECT BY PRIOR bom_code = rm_code ) AS total_qty
FROM table_name t
WHERE CONNECT_BY_ISLEAF = 1
START WITH bom_code = 'A'
CONNECT BY PRIOR rm_code = bom_code;
Output :
db<>fiddle her