how to query_posts by category slug - wordpress

Question

I am using the following code to list some pages on my wordpress site:
$args = array( 'posts_per_page' => 12, 'order'=> 'ASC', 'post_type' => 'tcp_product', 'paged' => $paged);
?>
<?php query_posts($args); ?>
<?php while (have_posts()) : the_post(); ?>
<a href="<?php the_permalink(); ?>" id="prod-link">
<?php if( has_sub_field('images') ): ?>
<?php $img = get_sub_field('image') ?>
<img src="<?php echo $img['sizes']['product-index-pic'] ?>" />
<?php endif; ?>
</a>
<?php endwhile; ?>
<!-- #posts -->
<div class="pagination">
<?php posts_nav_link( ' ', '<img src="' . get_bloginfo('template_url') . '/assets/images/prev.jpg" />', '<img src="' . get_bloginfo('template_url') . '/assets/images/next.jpg" />' ); ?>
</div>
<!-- .pagination -->
I am wondering if there would be a way to limit those based on a certain category slug?
Thanks in advance

Answer 1

You can use the variable category_name like this:
$args = array( 'category_name' => ***YOUR CATEGORY SLUG***, 'posts_per_page' => 12, 'order'=> 'ASC', 'post_type' => 'tcp_product', 'paged' => $paged);

Answer 2

tax_query is used to get the posts associated with certain taxonomy.
{tax} (string) - use taxonomy slug. Deprecated as of Version 3.1 in favor of 'tax_query'.
tax_query (array) - use taxonomy parameters (available with Version 3.1).
taxonomy (string) - Taxonomy.
field (string) - Select taxonomy term by ('id' or 'slug')
terms (int/string/array) - Taxonomy term(s).
include_children (boolean) - Whether or not to include children for hierarchical taxonomies. Defaults to true.
operator (string) - Operator to test. Possible values are 'IN', 'NOT IN', 'AND'.
$args = array(
'post_type' => 'tcp_product',
'posts_per_page' => 12,
'tax_query' => array(
array(
'taxonomy' => 'tcp_product_taxonomy',
'field' => 'slug',
'terms' => 'your-cat-slug'
)
)
);
$query = new WP_Query($args);
if ($query->have_posts()) {
while ($query->have_posts()) {
$query->the_post;
// do something
}
}