PDO advanced search from multiple tables - php

Question

I am trying to create a person search, based on multiple select boxes, radio buttons and dropdowns.
Some of the select boxes are arrays so I need to consider all of the selected options to show the results.
There are different tables for services, languages, about, work experience etc.
But something is wrong with my logic. At the moment, when I am trying the search it goes like this: I select English language from the language dropdow, but there is nobody who speaks English so there are no results which is correct. Then if I select one of the services (let's sat cleaning), then there will be one result because the same person has listed cleaning as their service, but this is wrong because he doesn't speak English.
I am using union all and LIKE in my query, but can somebody tell me why it still showing results? If i am doing something wrong, could you please point me in the right direction?
This is my query and PHP code so far:
if (isset($_POST['userServices']) && !empty($_POST['userServices'])){
$userServices = $_POST['userServices'];
for ($i = 0; $i < count($userServices); $i++) {
$services = $userServices[$i];
}
}
if (isset($_POST['languagesArray']) && !empty($_POST['languagesArray'])){
$languagesArray = $_POST['languagesArray'];
for ($i = 0; $i < count($languagesArray); $i++) {
$languages = $languagesArray[$i];
}
}
$search = $user_home->runQuery("
SELECT nanny_services.user_id, userFirstName
FROM hoidja.nanny_services
JOIN services on nanny_services.service_id = services.service_id
JOIN tbl_users ON tbl_users.user_id = nanny_services.user_id
WHERE (services.service_id LIKE :service_id)
GROUP BY nanny_services.user_id;
UNION ALL
SELECT user_language.user_id, userFirstName
FROM hoidja.user_language
JOIN languages on user_language.user_language_id = languages.user_language_id
JOIN tbl_users ON tbl_users.user_id = user_language.user_id
WHERE (languages.user_language_id LIKE :language_id)
GROUP BY user_language.user_id
");
$search->execute(array(
':service_id' => $services,
':language_id' => $languages,
));
$search_results = $search->fetchAll(PDO::FETCH_ASSOC);
echo json_encode($search_results);

Answer 1

Something like this
SELECT nanny_services.user_id, userFirstName
FROM hoidja.nanny_services
JOIN services on nanny_services.service_id = services.service_id
JOIN tbl_users ON tbl_users.user_id = nanny_services.user_id
WHERE (services.service_id = :service_id)
AND (languages.user_language_id = :language_id)
GROUP BY nanny_services.user_id;
without UNION