Hierarkiska frågor

Oracle-inställningar :

CREATE TABLE table_name ( GRAND_MODEL, WAIT_4_MODEL_NAME ) AS
SELECT 'test',  'test1' FROM DUAL UNION ALL
SELECT 'test',  'test2' FROM DUAL UNION ALL
SELECT 'test',  'test3' FROM DUAL UNION ALL
SELECT 'test2', 'test3' FROM DUAL UNION ALL
SELECT 'test3', 'test4' FROM DUAL UNION ALL
SELECT 'test4', 'test5' FROM DUAL;

Fråga :

SELECT REGEXP_SUBSTR( tests, '[^|]+', 1, 1 ) AS first_model,
       REGEXP_SUBSTR( tests, '[^|]+', 1, 2 ) AS second_model,
       REGEXP_SUBSTR( tests, '[^|]+', 1, 3 ) AS third_model,
       REGEXP_SUBSTR( tests, '[^|]+', 1, 4 ) AS fourth_model,
       REGEXP_SUBSTR( tests, '[^|]+', 1, 5 ) AS fifth_model,
       REGEXP_SUBSTR( tests, '[^|]+', 1, 6 ) AS sixth_model,
       REGEXP_SUBSTR( tests, '[^|]+', 1, 7 ) AS seventh_model,
       REGEXP_SUBSTR( tests, '[^|]+', 1, 8 ) AS eighth_model,
       REGEXP_SUBSTR( tests, '[^|]+', 1, 9 ) AS ninth_model
FROM   (
  SELECT SYS_CONNECT_BY_PATH( wait_4_model_name, '|' ) || '|' ||  grand_model AS tests
  FROM  table_name
  CONNECT BY PRIOR grand_model = wait_4_model_name
);

Utdata :

FIRST_MODEL SECOND_MODEL THIRD_MODEL FOURTH_MODEL FIFTH_MODEL SIXTH_MODEL SEVENTH_MODEL EIGHTH_MODEL NINTH_MODEL
----------- ------------ ----------- ------------ ----------- ----------- ------------- ------------ -----------
test1       test                                                                                                 
test2       test                                                                                                 
test3       test                                                                                                 
test3       test2                                                                                                
test3       test2        test                                                                                    
test4       test3                                                                                                
test4       test3        test                                                                                    
test4       test3        test2                                                                                   
test4       test3        test2       test                                                                        
test5       test4                                                                                                
test5       test4        test3                                                                                   
test5       test4        test3       test                                                                        
test5       test4        test3       test2                                                                       
test5       test4        test3       test2        test