Where can I insert the condition additionally into query for media list.
In a word I want to apply some filter regarding the postmeta table’s meta-value.
I tried to get the value with the following sql. But I didn’t get any change.

I modified the function “prepare_items()” in file wp-admin/includes/class-wp-media-list-table.php.

public function prepare_items() {

    global $wp_query, $post_mime_types, $avail_post_mime_types, $mode;

    /**
    * 
    * paul lee
    * 
    */
    $q_args = $_REQUEST;
    $meta_query = array(
        array(
            'key' => 'meta_value',
            'value' => '%cloudinary%',
            'compare' => 'NOT LIKE'
        )
    );
    $q_args['meta_query'] = $meta_query;

    list( $post_mime_types, $avail_post_mime_types ) = wp_edit_attachments_query( $q_args );
    /*-----------------------------------------------*/



    $this->is_trash = isset( $_REQUEST['attachment-filter'] ) && 'trash' === $_REQUEST['attachment-filter'];

    $mode = empty( $_REQUEST['mode'] ) ? 'list' : $_REQUEST['mode'];

    $this->set_pagination_args( array(
        'total_items' => $wp_query->found_posts,
        'total_pages' => $wp_query->max_num_pages,
        'per_page' => $wp_query->query_vars['posts_per_page'],
    ) );
}

I am not sure if I think wrong that the meta_query will be applied to postmeta table also.
I want your professional help.
Thanks

As said in comments, it’s not a good idea editing WP core files. You can easily modify the query that displays your media posts by adding the following code to a plugin or your theme’s functions.php

add_filter( 'pre_get_posts', '_wp_media_pre_get_posts' );

function _wp_media_pre_get_posts( $wp_query ) {
    global $pagenow;

    if( ! in_array( $pagenow, array( 'upload.php', 'admin-ajax.php' ) ) )
        return;

    $wp_query->set( 'meta_query', array(
        array(
            'key' => 'meta_value',
            'value' => '%cloudinary%',
            'compare' => 'NOT LIKE'
        )
    ) );

}