Query Database and Return the result - php

Question

I am having a problem for a while now and I can´t seem to solve it on my own.
I have made a website, this website is multilingual and it was made in wordpress.
In my "photo album" page when I sort the items in the default language (English) everything works fine, however if I change to another translation (ex.french), the name of the category changes and the tagged items don't appear anymore.
http://madebysylvie.be/collection
In my database I manage to find the table and the rows of each category, I want to be able access it in a different language, each one has an unique ID.
I know I have to grab the ID from the database of each category and return it to my PHP script.
This is my code,
<ul class="filter_portfolio">
<?php
// Get the taxonomy
$terms = get_terms('filter', $args);
// set a count to the amount of categories in our taxonomy
$count = count($terms);
// set a count value to 0
$i=0;
// test if the count has any categories
if ($count > 0) {
// break each of the categories into individual elements
foreach ($terms as $term) {
// increase the count by 1
$i++;
// rewrite the output for each category
$term_list .= '<li class="segment-'.$i.'">' . $term->name . '</li>';
// if count is equal to i then output blank
if ($count != $i)
{
$term_list .= '';
}
else
{
$term_list .= '';
}
}
// print out each of the categories in our new format
echo $term_list;
}
?>
</ul>
However I am not good enough to do this on my own, and I would be very happy if someone could help me out on this one.
I don't know how to query my database, and I am not shore how to modify the php in order to print it in the other languages.
Thanks

Answer 1

Please refer to the Wordpress documentation, the "Codex":
Class Reference/wpdb – Interfacing With the Database
Displaying Posts Using a Custom Select Query
Class Reference/WP Query –
Custom Queries – how to modify queries using hooks
But remember »Most of the time you can find the information you want without actually dealing with the class internals and globals variables. There are a whole bunch of functions that you can call from anywhere that will enable you to get the information you need.«
WP_Query example from the docs:
<?php
// The Query
$the_query = new WP_Query( $args );
// The Loop
if ( $the_query->have_posts() ) {
while ( $the_query->have_posts() ) {
$the_query->the_post();
echo '<li>' . get_the_title() . '</li>';
}
} else {
// no posts found
}
/* Restore original Post Data */
wp_reset_postdata();