Question

I have a table that looks like this.

| path_id | step | point_id | delay_time | stand_time | access |

| 202 | 1 | 111 | 0 | 0 | 7 |

Which lists point_id’s in step order.
E.g.: 111 – step 1, 181 – step 2, etc.

I need to write a query that would take point_id, select ALL values which have higher step within ALL path_id’s that have a given value and return a grouped set of point_id’s.

I am currently using this query

SELECT DISTINCT `pdb`.`point_id` AS `id` 
FROM `path_detail` AS `pda` INNER JOIN 
`path_detail` AS `pdb` ON pda.path_id = pdb.path_id 
 AND pda.step < pdb.step
WHERE 
(pda.point_id = 111) 
GROUP BY `pdb`.`path_id`

Which doesn’t seem to work too reliably.

Any suggestions?

Answer 1

Try:

SELECT Distinct `pdb`.`point_id` AS `id` 
FROM `path_detail` AS `pda`, `path_detail` AS `pdb`  
WHERE 
pda.point_id = 111
AND pda.path_id = pdb.path_id 
AND pda.step < pdb.step
Order by `pdb`.`point_id` ASC