Hello Petr,
Thank you.
I want to obtain this result: a list of categories such as: parent category -> subcategory
That's not true. Each link in categorylinks is from a page (cl_from, this can be a category page) to its parent category (cl_to).
Indeed I followed this structure, selecting only category pages and I obtained e.g. 690070 (sub category "Futurama", cl_from) to parent category "Comic_science_fiction" e.g. 690451 (sub category "World War II", cl_from) to parent category "Conflicts_in_1939"
so I my perception is the first example is correct, instead World War II should be parent of Conflicts_in_1939
Am I right or am I missing / misunderstood something?
If I look at the categorylinks for that category (cl_from = 690451) in the latest dump, I get some “conflicts” categories, then some “Wars involving X” categories and also few others, like “Modern Europe”. I don't see any parent category that would be missing.
That's correct for Modern Europe but if you compare with the page http://en.wikipedia.org/wiki/Category:World_War_II you see some links are missing in the sql dump, such as: http://en.wikipedia.org/wiki/Category:Military_deception_during_World_War_II or http://en.wikipedia.org/wiki/Category:Sociology_of_World_War_II
This is the list I obtain: the above sub categories are not present:
690451 1930s_conflicts 690451 1940s_conflicts 690451 20th-century_conflicts 690451 Categories_requiring_diffusion 690451 Conflicts_in_1939 690451 Conflicts_in_1940 690451 Conflicts_in_1941 690451 Conflicts_in_1942 690451 Conflicts_in_1943 690451 Conflicts_in_1944 690451 Conflicts_in_1945 690451 Global_conflicts 690451 Modern_Europe 690451 Wars_involving_Albania 690451 Wars_involving_Argentina 690451 Wars_involving_Australia 690451 Wars_involving_Austria 690451 Wars_involving_ .... [etc.]