$wpdb get_results - loop from specific category - php

Question

I have this code, its working good, but its gets posts from all categories. I need to get posts only from category ID 2. I tried to add "AND term_taxonomy_id = 2" to my code, but this didint work. Can somebody help me with this, my code:
<?php //loops all posts
$my_query = $wpdb->get_results
("SELECT * FROM `{$table_prefix}posts`, {$table_prefix}postmeta
WHERE {$table_prefix}posts.post_status = 'publish'
AND {$table_prefix}posts.id = {$table_prefix}postmeta.post_id
AND {$table_prefix}postmeta.`meta_key` = 'wpcf-data-nuo' ORDER BY if({$table_prefix}postmeta.`meta_value` = '' or {$table_prefix}postmeta.`meta_value` is null,1,0), {$table_prefix}postmeta.`meta_value` ASC LIMIT 12");
foreach($my_query as $post) {
setup_postdata($post);
?>

Answer 1

Please follow below code, Hope! its working
You can define the meta key for orderby parameter using the old method (I tested on WP 3.1.1)...
query_posts(
array( 'post_type' => 'services',
'order' => 'ASC',
'meta_key' => 'some_key',
'orderby' => 'meta_value', //or 'meta_value_num'
'meta_query' => array(
array('key' => 'order_in_archive',
'value' => 'some_value'
)
)
)
);
OR
For me, I wanted to order by a numeric field and I had to use 'type' => 'NUMERIC' inside the meta query.
This issue in general is cleared up in WordPress 4.2 by using named queries. e.g.
$args = array(
'post_type' => 'services',
'orderby' => 'order_clause',
'meta_query' => array(
'order_clause' => array(
'key' => 'order_in_archive',
'value' => 'some_value',
'type' => 'NUMERIC' // unless the field is not a number
)));
Reference link for set the meta value in query: https://rudrastyh.com/wordpress/meta_query.html

Answer 2

You can do it by WP_QUERY instead writing custom Query.
The query to get the results and then your custom sort order by altering the WP_QUERY if default order parameters not work as expected.
$args = array(
'post_type' => 'post',
'posts_per_page' => 8,
'cat' => 2,
'meta_key' => 'wpcf-data-nuo',
'orderby' => 'meta_value_num',
'order' => 'ASC'
);
add_filter('posts_orderby', 'filter_query');
$q = new WP_Query($args);
remove_filter('posts_orderby', 'filter_query');
function filter_query( $orderby_statement ) {
global $table_prefix;
$orderby_statement .= " if({$table_prefix}postmeta.`meta_value` = '' ";
$orderby_statement .= " or {$table_prefix}postmeta.`meta_value` is null,1,0), {$table_prefix}postmeta.`meta_value`";
return $orderby_statement;
}
Note: Do not remove spaces from $orderby_statement .= because it require spaces while running query.
If it still doesn't work, then add var_dump($orderby_statement); before return $orderby_statement; then copy the SQL and add it in your question so it will help us to understand what is the issue.