WordPress Custom Query for Taxonomy - mysql

Question

I have to edit somebody's code and I am not familiar with querying posts using the method they are. I have tried editing the query to various alternatives, however I am having no luck. I want to change the following query to select data from a custom taxonomy called 'job_cat' where the value equals a POST value. The code is below:
$querystr = "
SELECT DISTINCT wposts.*
FROM $wpdb->posts wposts
LEFT JOIN $wpdb->postmeta wpostmeta ON wposts.ID = wpostmeta.post_id
LEFT JOIN $wpdb->postmeta wpostmeta2 ON wposts.ID = wpostmeta2.post_id
LEFT JOIN $wpdb->term_relationships ON (wposts.ID = $wpdb->term_relationships.object_id)
LEFT JOIN $wpdb->term_taxonomy ON ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id)
WHERE wp_term_taxonomy.term_id = 94";
// If a job type is set and not equal to nothing or any jobs
if(isset($_POST['search-location']) && $_POST['search-location'] !== "" && $_POST['search-location'] !== "All") {
$querystr .= " AND (wpostmeta2.meta_key = 'region' AND wpostmeta2.meta_value = '".$_POST['search-location']."')";
}
$querystr .= " ORDER BY post_date DESC LIMIT 50";
//Execute
//echo $querystr;
$pageposts = $wpdb->get_results($wpdb->prepare($querystr, OBJECT));
Any help would be great!!

Answer 1

This code is extremely dangerous to use in a production WordPress site. You need to remove it and any other template file larded up with SQL queries like this.
Instead, use WP_Query which automatically sanitizes your SQL requests. It has a huge number of parameters you can set to query anything from WordPress. Here is an example using WP_Query to get posts by a given taxonomy, with tax_query.
<?php
// 1- Setup an argument to give to WP_Query
$taxonomy_args = array(
// 2- use the tax_query to examine a taxonomy
'tax_query' => array(
array(
'taxonomy' => 'job_cat',
'terms' => 'XYZ',
'field' => 'slug',
'include_children' => true,
'operator' => 'IN'
)
),
// 3- Make sure to define how many posts and what post-type they should be
'posts_per_page' => 50,
'post_type' => 'search-location',
);
$s = new WP_Query( $some_args );
if ( $s->have_posts() ) : $s->the_post();
// 4- Here you will manipulate the data you get back
endif;
?>