Problem with multiple loops in wordpress theme

Question

I am using multiple loops like this

            <?php
$posts = get_posts('numberposts=1&order=DESC&orderby=post_date&category='.get_cat_ID( 'سیاست' ));


foreach ($posts as $post) : start_wp(); ?>
<?php 
    if ( has_post_thumbnail() ) {
    the_post_thumbnail();
    }

    ?>


                <div class="content">
                              <h2><a href="<?php the_permalink()?>"><?php the_title()?></a></h2>
                    <p><?php the_excerpt(); ?></p>
                    <hr/>
                    <?php   
endforeach;
?>

In most part of my theme like sidebar, footer, slidershow with different category, the problem that I've faced with is that when I'm using the following loop in archive.php or category.php to show the post data(like title, excerpt and feature image) based on category it doesn't show me anything. When I remove all above loop, it works. This is the loop in my archive or category.php to show post excerpt and title:

<?php if(have_posts()):?>
        <?php while ( have_posts() ) : the_post(); ?>  
                <?Php the_title(); ?><br/>
        <?php endwhile; ?>
        <?php endif;?>

I remember a time that I had this problem and solved by using wp_reset_query after each loop but it doesn't work now. Maybe wp_reset_query doesn't work for foreach loop.

Answer 1

The proper way to set up a secondary query, using your example code. Instead of this:

$posts = get_posts('numberposts=1&order=DESC&orderby=post_date&category='.get_cat_ID( 'سیاست' ));

Do this:

// Query args
$custom_cat_args = array(
    'posts_per_page' => 1,
    'order' => 'DESC',
    'orderby' => 'post_date',
    'cat' => get_cat_ID( 'سیاست' )
);
// Instantiate query
$custom_cat_query = new WP_Query( $custom_cat_args );
// Instantiate loop
if ( $custom_cat_query->have_posts() ) : while ( $custom_cat_query->have_posts() ) : $custom_cat_query->the_post();
    // Normal loop markup here
// Close loop
endwhile; endif;
// Restore $post global
wp_reset_postdata();

Using this method, your custom query will play nicely with your main loop query, and any other secondary queries.