我做了一个简单的循环来显示类别和品牌的产品库（自定义分类法）

这里是我的循环：

<?php 
$args = array( 
    \'post_type\' => \'product\', 
    \'posts_per_page\' => 4, 
    \'orderby\'      => \'DESC\',   

   \'tax_query\'     => array(
        \'relation\' => \'AND\',
         array( 
            \'taxonomy\' => \'brands\',
            \'field\'     => \'id\',
            \'terms\' => array($category)
       ),
         array( 
            \'taxonomy\' => \'product_cat\',
            \'field\'     => \'id\',
            \'terms\' => array($category)
    )
),  

    );
    $wp_query = null;
    $wp_query = new WP_Query( $args );?>

但没什么可展示的。当我改变时

        \'relation\' => \'AND\', to \'relation\' => \'OR\',

仅按品牌展示的产品。

Practice with the following Nitin Singh Chouhan\'S code and Champeau\'s suggestion, but still failed

 <?php 
 $args = array(
\'post_type\' => array(\'post\',\'product\'),
\'tax_query\' => array(
      \'relation\' => \'AND\',
   array(
     \'taxonomy\' => \'product_cat\',
     \'terms\' => array($category),
     \'field\' => \'id\'
   ),
   array(
     \'taxonomy\' => \'brands\',
     \'terms\' => array($categories_brands),
     \'field\' => \'id\'
      ),
   )
 ); 

     );
     $wp_query = null;
     $wp_query = new WP_Query( $args );?>

            <?php if ( $wp_query -> have_posts()) : ?>
        <?php while ( $wp_query -> have_posts()) : $wp_query -> the_post(); ?>

        <?php the_title(); ?>

        <?php 
        endwhile;
        wp_reset_query();
        endif;
        ?>

有人能帮我吗？

谢谢你的帮助。

$args = array(
    \'post_type\' => array(\'post\',\'product\'),
    \'tax_query\' => array(
          \'relation\' => \'AND\',
       array(
         \'taxonomy\' => \'product_cat\',
         \'terms\' => 82,
         \'field\' => \'id\'
       ),
       array(
         \'taxonomy\' => \'brand\',
         \'terms\' => 81,
         \'field\' => \'id\'
       ),
    )
);
query_posts($args);

   if ( have_posts() ) {
    while ( have_posts() ) {
        the_post();         
        the_title();        
    } 
}