Struggling writing a nested query - mysql

Question

I've got the following tables:
Products:
+---------------------------+
|id|name |details |price|cn|
|__|_____|_________|_____|__|
| 1|pen |somethi |100 |10|
| 2|paper|something|30 |11|
+---------------------------+
Categories:
+----------------------------+
|id | name |parent_id |
|____________________________|
|1 | granny | 0 |
|2 | dad | 1 |
|3 | grandson | 2 |
|4 | grandson 2| 2 |
+----------------------------+
Products2categories:
+-------------------------------+
| id | product_id | category_id|
|_______________________________|
| 1 | 1 | 3 |
| 2 | 1 | 2 |
| 3 | 1 | 1 |
+-------------------------------+
I want to do a query that will return all of the categories that some product is related to.
for example:
When I supply a product ID of 1 I would like to get as a result the result
grandson,dad,granny (name of the categories that this product is related to)
This is my attempt:
SELECT `categories`.`name`
FROM `categories`
JOIN (
SELECT `products2categories`.`category_id`,`products2categories`.`product_id`
FROM `products2categories` a
JOIN `products`
ON `products`.`id` = `products2categories`.`product_id`
)
ON `categories`.`id` = `products2categories`.`category_id`
I've got the following error:
Every derived table must have its own alias
I would like to get some help here :)
Thanks in advance!

Answer 1

Unless I'm misunderstanding your statement, I believe you're overcomplicating things. Based on your verbal description of what you want (and ignoring your code), this will do what you're asking:
SELECT name FROM categories WHERE id IN (SELECT id FROM products2categories WHERE product_id = 1);
EDIT: HERE IS A COMPLETE TEST
CREATE TABLE `categories` (
`id` int(11) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
`parent_id` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `categories` VALUES (1,'granny',0),(2,'dad',1),(3,'grandson',2),(4,'grandson 2',2);
CREATE TABLE `products` (
`id` int(11) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
`details` varchar(255) DEFAULT NULL,
`price` int(11) DEFAULT NULL,
`cn` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `products` VALUES (1,'pen','somethi',100,10),(2,'paper','something',30,11);
CREATE TABLE `products2categories` (
`id` int(11) DEFAULT NULL,
`product_id` int(11) DEFAULT NULL,
`category_id` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `products2categories` VALUES (1,1,3),(2,1,2),(3,1,1);
mysql> SELECT name FROM categories WHERE id IN (SELECT id FROM products2categories WHERE product_id = 1);
+----------+
| name |
+----------+
| granny |
| dad |
| grandson |
+----------+
3 rows in set (0.00 sec)

Answer 2

Well, I've just found out that I was doing it way too hard that it actually is.
For who-ever will come across it somewhen in the future, here is the solution:
SELECT `categories`.`name`
FROM `categories`
JOIN `products2categories`
ON `categories`.`id` = `products2categories`.`category_id`
WHERE `products2categories`.`product_id` = 1