Impossible to exclude categries in a category listing

[dimitryz]

Setting the 'category__not_in' query_var in a WP_Query object does nothing if 'category_name' is also present. The consequence is that it's impossible to hide the posts of some child categories for a category listing.

The offending code is in line 1843:

$whichcat = " AND $wpdb->term_taxonomy.taxonomy = 'category' ";

A dot (.) should be added before the equal (=) to indicate concatenation:

$whichcat .= " AND $wpdb->term_taxonomy.taxonomy = 'category' ";

The proposed solution enabled the addition of categories ('category__in') and exclusion of categories ('category__not_in') when the following condition is met:

if ( '' != $q['category_name'] && !$this->is_singular ) {

[dd32]

What would be the use-case of this?

category_name is asking to query for a specific item, category__not_in is saying, for the following generic query, i do not want the following items to be there.. When would they be used together?

[dimitryz]

When you're listing the posts for a category. Currently, all posts for that category and posts for that category's children are displayed. If you wanted to exclude the posts of one or more child categories, 'category__not_in' should do the trick.

[scribu]

You can use 'postsnot_in' instead, as I'm pretty sure allowing 'categorynot_in' together with 'category_name' will have hidden side effects.

[dimitryz]

I'm not sure about scribu's answer. Excluding posts is more trouble since those posts must first be retrieved. That may be a *lot* of posts.

I also don't understand that you mean by category_name. 'category__not_in' is used with an array of term_ids, not names.

[scribu]

I can see the use-case for this now.

Also see #12891

[upyup]

I have the same problem on v3.0.1

the goal being to set a user filter on specific categories (chosen in the plugin options page)

If the user chose the category 4 ("Adultes" categorie) and then goes to /category/adultes , he is presented the posts from this categories instead of the expected "No post found" page

When changing line 1938

$whichcat = " AND $wpdb->term_taxonomy.taxonomy = 'category' ";

into

$whichcat .= " AND $wpdb->term_taxonomy.taxonomy = 'category' ";

the filter works as a charm

[scribu]

Please try it with version 3.1-alpha.

'Version' represents the earliest version in which the bug is reproducible.

[wonderboymusic]

This problem has been washed away by time. Pro tip: the string "$whichcat" no longer exists in the WordPress codebase.

[SergeyBiryukov]

#5248