I think I can help with questions 1 and 3... see below,
----- Original Message -----
From: "Alex E.Wintermann" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, December 04, 2003 11:44 PM
Subject: Tree-like structure: make it simply
> Hello mysql,
>
> I have some table:
> /* BEGIN DUMP *************************************************/
> CREATE TABLE `sp_tovar_vid` (
> `id` int(11) NOT NULL auto_increment,
> `id_tovar_vid` int(11) NOT NULL default '0',
> `name` varchar(100) NOT NULL default '',
> `description` varchar(255) NOT NULL default '',
> UNIQUE KEY `id` (`id`)
> );
>
> INSERT INTO `sp_tovar_vid` VALUES (0, 0, 'root', 'root category');
> INSERT INTO `sp_tovar_vid` VALUES (7, 0, 'cat.1', '');
> INSERT INTO `sp_tovar_vid` VALUES (8, 0, 'cat.2', '');
> INSERT INTO `sp_tovar_vid` VALUES (9, 0, 'cat.3', '');
> INSERT INTO `sp_tovar_vid` VALUES (10, 0, 'cat.4', '');
> INSERT INTO `sp_tovar_vid` VALUES (11, 0, 'cat.5', '');
> INSERT INTO `sp_tovar_vid` VALUES (12, 7, 'subcat 1', '(to cat.1)');
> INSERT INTO `sp_tovar_vid` VALUES (13, 7, 'subcat 2', '(to cat.1)');
> INSERT INTO `sp_tovar_vid` VALUES (14, 7, 'subcat 3', '(to cat.1)');
> INSERT INTO `sp_tovar_vid` VALUES (15, 9, 'subcat 1', '(to cat.3)');
> INSERT INTO `sp_tovar_vid` VALUES (16, 9, 'subcat 2', '(to cat.3)');
> INSERT INTO `sp_tovar_vid` VALUES (17, 9, 'subcat 3', '(to cat.3)');
> INSERT INTO `sp_tovar_vid` VALUES (18, 13, 'subsubcat 1', '(to subcat.2
> to cat.1)');
> /* END DUMP ****************************************************/
>
> _QUESTION 1_: in what way should i run query to restore table with
> `id`' like in dump? (`id` is auto_increment)
>
either omit the `id` field when re-loading the data, e.g.
INSERT INTO `sp_tovar_vid` (`id_tovar_vid`,`name`,`description`) VALUES (0,
'root', 'root category');
or, replace the `id` values with an empty string when re-loading the table
data, e.g.
INSERT INTO `sp_tovar_vid` VALUES ('', 0, 'cat.1', '');
both techniques prompt mysql to reassign the `id` values.
note that I do not think it is wise/possible to run a query to restore (or
clean up) the auto_increment values without re-loading the table data.
> _QUESTION 2_: how to display table with columns=
> ('parent_category.name' ,'category.name')?
> i tried this:
> /***/
> SELECT t1.`name`,t2.`name` FROM `sp_tovar_vid` AS t1, `sp_tovar_vid`
> AS t2 WHERE t1.`id`=t2.`id_tovar_vid` ORDER BY t1.`name`,t2.`name`;
> /***/
> How to make it more simply?
>
> _QUESTION 3_: how to display string:
> "subsubcat 1 - subcat.2 - cat.1"
> if we have only `id`=18 ?
>
use SELECT IF(id=18, true_expression, false expression) FROM table...
I'm not clear what you mean by "subsubcat 1 - subcat.2 - cat.1"... minus, or
some sort of string concatenation?
true expression might be field1 - field2, or CONCAT(field1, field2, ...)
> --
> Best regards,
> Alex mailto:[EMAIL PROTECTED]
>
>
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