Wordpress meta query not working

Question

 add_action( 'pre_get_posts' , 'my_pre_get_posts' );
    Function my_pre_get_posts( $query ) {
        $value= $_GET['s'];
        if( $query->is_main_query() && $query->is_search()) {
            $query->set( 
              'meta_query',
              array( 
                array(
                  'key' => 'pdf_content',
                  'value' => $value,
                  'compare' => 'LIKE'
                )  
              ) 
            ); 
         }
    }

I am not getting any result from this query please help me?

WP_Query Object ( [query] => Array ( [s] => construction [post_type] => iep_section ) [query_vars] => Array ( [s] => construction [post_type] => iep_section [error] => [m] => [p] => 0 [post_parent] => [subpost] => [subpost_id] => [attachment] => [attachment_id] => 0 [name] => [pagename] => [page_id] => 0 [second] => [minute] => [hour] => [day] => 0 [monthnum] => 0 [year] => 0 [w] => 0 [category_name] => [tag] => [cat] => [tag_id] => [author] => [author_name] => [feed] => [tb] => [paged] => 0 [meta_key] => [meta_value] => [preview] => [sentence] => [title] => [fields] => [menu_order] => [embed] => [category__in] => Array ( ) [category__not_in] => Array ( ) [category__and] => Array ( ) [post__in] => Array ( ) [post__not_in] => Array ( ) [post_name__in] => Array ( ) [tag__in] => Array ( ) [tag__not_in] => Array ( ) [tag__and] => Array ( ) [tag_slug__in] => Array ( ) [tag_slug__and] => Array ( ) [post_parent__in] => Array ( ) [post_parent__not_in] => Array ( ) [author__in] => Array ( ) [author__not_in] => Array ( ) [meta_query] => Array ( [0] => Array ( [key] => pdf_content [compare] => LIKE [value] => construction [type] => char ) ) ) [tax_query] => WP_Tax_Query Object ( [queries] => Array ( ) [relation] => AND [table_aliases:protected] => Array ( ) [queried_terms] => Array ( ) [primary_table] => [primary_id_column] => ) [meta_query] => [date_query] => [post_count] => 0 [current_post] => -1 [in_the_loop] => [comment_count] => 0 [current_comment] => -1 [found_posts] => 0 [max_num_pages] => 0 [max_num_comment_pages] => 0 [is_single] => [is_preview] => [is_page] => [is_archive] => 1 [is_date] => [is_year] => [is_month] => [is_day] => [is_time] => [is_author] => [is_category] => [is_tag] => [is_tax] => [is_search] => 1 [is_feed] => [is_comment_feed] => [is_trackback] => [is_home] => [is_privacy_policy] => [is_404] => [is_embed] => [is_paged] => [is_admin] => [is_attachment] => [is_singular] => [is_robots] => [is_posts_page] => [is_post_type_archive] => 1 [query_vars_hash:WP_Query:private] => fbc82700aadf968ad3d001310266de18 [query_vars_changed:WP_Query:private] => [thumbnails_cached] => [stopwords:WP_Query:private] => [compat_fields:WP_Query:private] => Array ( [0] => query_vars_hash [1] => query_vars_changed ) [compat_methods:WP_Query:private] => Array ( [0] => init_query_flags [1] => parse_tax_query ) )

Answer 1

When using LIKE clause, you should be using % to the start and end of the value to make it match with the existing values. So your query should look like this.

add_action( 'pre_get_posts' , 'my_pre_get_posts' );
function my_pre_get_posts( $query ) {
    $value= '%'.$_GET['s'].'%';
    if( $query->is_main_query() && $query->is_search() ) {
        $query->set( 
          'meta_query',
          array( 
            array(
              'key' => 'pdf_content',
              'value' => $value,
              'compare' => 'LIKE'
            )  
          ) 
        ); 
     }
}

Answer 2

I fixed the problem by adding this code in search query

$args = array(
    'post_type'=> 'iep_section',

    'order'    => 'ASC',
    'meta_query' => array(
        array(
            'key' => 'pdf_content',
            'value' => $value,

            'compare' => 'LIKE'
        )
    )
);

query_posts( $args );