PHP/MySQL Query Problem - Not querying properly

Hello all,

I'm having a little trouble with an SQL query. My script consists of the following:

Parent/child categories (Top level categories have column 'parent' = 0).
Data items held within child categories

In the data table I have the columns 'topparent' (the top level category) and 'childparent' (the child category it is in).

In the categories table there is the column 'string' which I need to extract. The idea is to list all data items - From this query I need to be able to use the 'string' of the 'topparent' category and the string of the 'childparent' category.

So far I've only been able to output just one of the 'string' values and cannot quite figure out how to get both of them.

Any help would be much apperciated.

Thanks

 

I assume you have a table
[category_id_parent, category_id_child, other_data]
and want category->string for both ids ?

$sql = ("SELECT
a.data,
c1.string,
c2.string
FROM
datatable AS a
JOIN
categories AS c1
ON
a.topparent = c1.categoryid
JOIN
categories AS c2
ON
a.childparent = c2.categoryid";

something like that ?

 

By using that method I have the following.

SELECT
	tutorial.ID,
	tutorial.type,
	tutorial.string,
	tutorial.name,
	tutorial.description,
	tutorial.url,
	tutorial.parent,
	tutorial.date_added,
	tutorial.avatar,
	C1.string,
	C2.string,
	user.username
FROM
	tutorial, user
JOIN
	tutorial_cat AS C1
ON
	tutorial.topparent = C1.ID
JOIN
	tutorial_cat AS C2
ON
	tutorial.parent = C2.ID
WHERE
	tutorial.active = 1
	&& user.ID = tutorial.authorID
ORDER BY
	tutorial.date_added DESC

Code (markup):

The error Im getting is 'Cant execute query Unknown column 'tutorial.topparent' in 'on clause''.

The table tutorial does have a column called 'topparent'.

Just to clarify:
'topparent' = top level category
'parent' = child level category

Thanks

 

Replace "tutorial, user" with "(tutorial, user)".


http://dev.mysql.com/doc/refman/5.0/en/join.html

 

It works great
Thanks to both of you.