sagi sagi - 4 months ago 16
SQL Question

Hierarchical queries

I've created some sort of "dependencies" table that contain the entire dependencies of ours night process.

The table looks like this:

GRAND_MODEL | WAIT_4_MODEL_NAME
test test1
test test2
test test3
test2 test3
test3 test4
test4 test5


This table means ->
test
needs to wait for
test1
,
test2
,
test3
in order to finish, but also it needs to wait for
test4
and
test5
, because
test3/4
waits for them .
test1
doesn't wait for anything ,
test2
waits for
test3
and therefore also for
test4
and therefore
test5
.

So the result should look something like this:

FIRST_MODEL | SECOND_MODEL | THIRD_MODEL | FORTH_MODEL | FIFTH_MODEL | SIXTH_MODEL
test5 test4 test3 test2 test NULL
test5 test4 test3 test NULL NULL
test4 test3 test2 test NULL NULL
.................................


What I've tried :

SELECT distinct prior wait_4_model_name as first_m,
wait_4_model_name as second_m,
grand_model as third_m
from (SELECT distinct grand_model, wait_4_model_name
FROM DEL_SAGI_FOR_HIERARCHY)
connect by NOCYCLE prior grand_model = wait_4_model_name


But that only generates the first level of the hierarchy.

Thanks in advance.

EDIT: Note that there can be opposite dependencies ,
test
waits for
test1
and
test1
waits for
test
(each model is big, so it's possible for a part of the model to wait for a part of another model)

MT0 MT0
Answer

Oracle Setup:

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;

Query:

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
);

Output:

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