Hi,
in oracle we have connect by prior for hierachical data traversal.
in mysql, you can use group_concat like this :
mysql> select parentid, group_concat(id) from ids
-> group by parentid;
+----------+------------------+
| parentid | group_concat(id) |
+----------+------------------+
| 0 | 1 |
| 1 | 2,5 |
| 2 | 3,4 |
| 4 | 6 |
+----------+------------------+
4 rows in set (0.13 sec)
unless your need is more complex.
if you use php, you can look at
http://www.sitepoint.com/article/hierarchical-data-database
Mathias
Selon Marcus Bointon <marcus@stripped>:
> I have a table that represents a tree structure via a self-join. I'd
> like to get hold of all parent records in a single query - is such a
> thing possible? e.g. given
>
> id parentid
> 1 0
> 2 1
> 3 2
> 4 2
> 5 1
> 6 4
>
> If I was starting with record 4, I would want it to return records 2
> and 1 (probably in that order), starting from 5 would just give me 1
> etc. It needs to support arbitrary depth, hence the need for recursion.
>
> Can I do this in one go, or do I have to query iteratively until I
> encounter a zero reference?
>
> Marcus
> --
> Marcus Bointon
> Synchromedia Limited: Putting you in the picture
> marcus@stripped | http://www.synchromedia.co.uk
>
>
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