WP_Query parameter conflict

Question

I am writing a query to retrieve instances of a custom post type I created called "Specialist". In the query I specify a name and more than one taxonomy.
I want to retrieve just those specialist which respect both parameters.
If I run the two queries separately, the correct specialists are returned but when I integrate the two in one single query, it seems that the post_name takes the priority on the taxonomy.

For example, if I run the query asking for a specialist named test with taxonomy therapist, I have back the specialist called test even if it does not have a therapist taxonomy.

Here is the code:

$args = array(
    'post_type'=>'specialist',
    'name' => 'test',
    'tax_query' => array(
        array(
            'taxonomy' => 'type',
            'field' => 'slug',
            'terms' => 'therapist'
        )
    )
);

$specialists = new WP_Query($args);

Answer 1

Is your post type non-hierarchical like a post - or hierarchical like a page? It will determine which slug parameter you should be using in WP_Query:

name (string) - non-hierarchical (post) slug.
pagename (string) - hierarchical (page) slug.

Also, the tax_query should have the operator parameter. Possible values are 'IN', 'NOT IN', 'AND'. You should set it to 'AND'. This could be a solution:

$args = array(
    'post_type'=>'specialist',
    'postname' => 'test',
    'tax_query' => array(
        array(
            'taxonomy' => 'type',
            'field' => 'slug',
            'terms' => 'therapist',
            'operator'=> 'AND'
        )
    )
);

$specialists = new WP_Query($args);

If it really isn't working, then you could always do a workaround by creating a filtering function to add the where clause to the query

function filter_where( $where = '' ) {
    // post_name
    $where .= " AND $wpdb->posts.post_name = 'test'";
    return $where;
}
add_filter( 'posts_where', 'filter_where' );
$query = new WP_Query( $args );
remove_filter( 'posts_where', 'filter_where' );

Answer 2

Yes your query is wrong, your are querying post name 'Test' which is 'specialist' post type and taxonomy is 'therapist'.

correct one should be any post_name from 'specialist' post type with which has Type taxonomy and term is 'therapist'.

$args = array(
'post_type'=>'specialist',
'tax_query' => array(
    array(
        'taxonomy' => 'type',
        'field' => 'slug',
        'terms' => 'therapist'
    )
)
);

specialists = new WP_Query($args);

I think this should be fine.