And/Or Category Query

Question

I'm having a lot of trouble using php query_posts(array('category__and'=>array(1,3))) - it seems to be pulling anything that's in category 1 regardless of whether it's also in category 3 and I only want the posts if they exist in both categories. And ultimately, I need a bunch of OR statements anyway, so is there a better way than query_posts to do this?

I want a page of posts that exist in a variety of multiple categories -- i.e:

categories 1 AND 3 OR categories 1 AND 5 OR categories 1 AND 6

But not categories 1 AND 4

Any help would be greatly appreciated. Thanks.

Answer 1

Strange, that usage of category__and should be working.

As for following logic I don't think you can accomplish anything that complex with query parameters. There are several possible ways to deal with it that I can think of:

• simplify category structure and/or selection logic;
• modify raw SQL with posts_where filter;
• store selection criteria in post meta.

Answer 2

You might be able to achieve something like what you're looking for with the tax_query argument.

In your case (untested, may yet fail), something like this will serve to get posts (in category 1) AND (in either category 3, 5, or 6) AND (NOT in category 4):

$tax_query = array(
        'relation' => 'AND',
    array(
        'taxonomy' => 'category',
        'terms' => array( 1 ),
    ),
    array(
        'taxonomy' => 'category',
        'terms' => array( 3, 5, 6 ),
    ),
    array(
        'taxonomy' => 'category',
        'terms' => array( 4 ),
        'operator' => "NOT IN"
    ),
);

query_posts( array( 'tax_query' => $tax_query ) );

Answer 3

You should be able to do it using the new tax_query arguments, like so.

query_posts( array(
    'tax_query' => array(
        'relation' => 'OR',
        array(
            'taxonomy' => 'category',
            'field' => 'slug',
            'terms' => array('term1', 'term3'),
            'operator' => 'AND'
        ),
        array(
            'taxonomy' => 'category',
            'field' => 'slug',
            'terms' => array('term1', 'term5'),
            'operator' => 'AND'
        ),
        array(
            'taxonomy' => 'category',
            'field' => 'slug',
            'terms' => array('term1', 'term6'),
            'operator' => 'AND'
        )
    )
) );

All category/tag parameters are just wrappers for tax_query's to now, so when you use category__in or any of the others, you're essentially just taking a shortcut to writing out a tax_query.