Ticket #12891: eager.php

<?php

function wp_tax_and() {
        $args = func_get_args();

        return wp_tax_group('AND', $args);
}

function wp_tax_or() {
        $args = func_get_args();

        return wp_tax_group('OR', $args);
}

function wp_tax_group($op, $args) {
        return "(" . implode(" $op ", $args) . ")";
}

function wp_tax($taxonomy, $terms, $field = 'term_id') {
        return _wp_tax($taxonomy, $terms, $field, true);
}

function wp_tax_not($taxonomy, $terms, $field = 'term_id') {
        return _wp_tax($taxonomy, $terms, $field, false);
}

function _wp_tax($taxonomy, $terms, $field, $in) {
        global $wpdb;

        $terms = (array) $terms;

        switch ( $field ) {
                case 'term_taxonomy_id':
                        $terms = implode( ',', array_map('intval', $terms) );
                break;

                case 'term_id':
                        $terms = implode( ',', array_map('intval', $terms) );
                        $terms = $wpdb->prepare("
                                SELECT term_taxonomy_id
                                FROM $wpdb->term_taxonomy
                                WHERE taxonomy = %s
                                AND term_id IN ($terms)
                        ", $taxonomy);
                break;

                case 'slug':
                case 'name':
                        $terms = "'" . implode( "','", esc_sql($terms) ) . "'";
                        $terms = $wpdb->prepare("
                                SELECT term_taxonomy_id
                                FROM $wpdb->term_taxonomy
                                INNER JOIN $wpdb->terms USING (term_id)
                                WHERE taxonomy = %s
                                AND $field IN ($terms)
                        ", $taxonomy);
        }

        $operator = $in ? 'IN' : 'NOT IN';

        return "term_taxonomy_id $operator ($terms)";
}

function wp_tax_query($query) {
        global $wpdb;
        return "SELECT object_id FROM $wpdb->term_relationships WHERE " . $query;
}

// Example
$query = wp_tax_query(wp_tax_and(
        wp_tax_or(
                wp_tax( 'post_category', 59 ),
                wp_tax( 'post_tag', 'web', 'slug' )
        ),
        wp_tax_not( 'post_category', 24 ),
        wp_tax_not( 'post_tag', 'wordpress', 'slug' )
));

var_dump($query);