This problem is giving me a real headache.
I have two tables in my database that solves sorting of categories with the help of a design called “Closure table”. The first table is called categories, and the other one is named categoriesPaths.
Categories is simply a language-based table:
id | name
----------------
0 | Category 1
1 | Category 2
CategoriesPaths looks like this:
parent | children | level
-----------------------
1 | 1 | 0
1 | 2 | 1
2 | 2 | 0
To delete a path together with it’s eventual child nodes, I run the following query: ($top is the top parent node level the deletion will begin at)
DELETE d FROM CategoriesPaths children
JOIN CategoriesPaths a USING (children)
WHERE a.parent = $top;
What I want to do is change the query to also delete the representative paths in the categories table. Unfortunately I have not enough SQL knowledge to do this. I tried to to make a workaround with a foreach loop before the query, but that fails to delete, since the categoriestable is referenced to categoriesPaths…
By that said, I am pretty much stuck.
If anyone wish to learn more about the closure table design, here’s a reference to the slideshare in which I learned it from: http://www.slideshare.net/billkarwin/sql-antipatterns-strike-back
Why not use a transaction?
http://www.firstsql.com/tutor5.htm