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Posted by Mikhail Kovalev on 12/05/07 18:16
On 5 Des, 17:26, Toby A Inkster <usenet200...@tobyinkster.co.uk>
wrote:
> Mikhail Kovalev wrote:
> > $array[112][COUNT] = 10;
> > $array[112][NEXT][225][COUNT] = 3;
> > $array[112][NEXT][225][NEXT][930][COUNT] = 1;
> > $array[112][NEXT][225][NEXT][930][NEXT] = array();
> > $array[112][NEXT][11][COUNT] = 5;
> > $array[112][NEXT][11][NEXT] = array();
>
> > An address is an array, f ex array(112, 225, 930)
>
> If $array[112][NEXT][11] exists, does that imply that
> $array[113][NEXT][11] cannot exist?
>
> i.e. Can 11 have only one "parent" or multiple?
>
> If it can only have one parent, then I'd suggest using the structure
> suggested by "C". If '11' can have more than one parent, then a classic
> tree structure is out of the window, so I'd suggest a simple string key,
> like this:
>
> CREATE TABLE nodes
> (
> node_address varchar(1024) NOT NULL PRIMARY KEY,
> node_count integer
> );
>
> To add counts to the database, you'd use:
>
> INSERT INTO nodes VALUES ('112', 10);
> INSERT INTO nodes VALUES ('112/225', 3);
> INSERT INTO nodes VALUES ('112/225/930', 1);
> INSERT INTO nodes VALUES ('112/11', 5);
>
> To retrieve the count for key array(112, 225, 930), you'd use:
>
> SELECT node_count
> FROM nodes
> WHERE node_address='112/225/930';
>
> To find a list of descendant nodes of '112', you'd use:
>
> SELECT node_address
> FROM nodes
> WHERE node_address LIKE '112/%';
>
> Or to find just child nodes (i.e. no grandchildren, etc):
>
> SELECT node_address
> FROM nodes
> WHERE node_address LIKE '112/%'
> AND NOT node_address LIKE '112/%/%';
>
> By the way -- do yourself a favour and stop naming your functions things
> like function_9() and function_10(), and variables like $array_3. If you
> have to come back to this code after 2 or 3 months away from it, you will
> have forgotten what they all do. Give them memorable names.
>
> --
> Toby A Inkster BSc (Hons) ARCS
> [Geek of HTML/SQL/Perl/PHP/Python/Apache/Linux]
> [OS: Linux 2.6.17.14-mm-desktop-9mdvsmp, up 10 days, 22:57.]
>
> Sharing Music with Apple iTunes
> http://tobyinkster.co.uk/blog/2007/11/28/itunes-sharing/
Testing it! Forever grateful for the examples!=)
Also, see my reply to Norman below.
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