PHP/MySQL query find string in field - php

Question

Ive written a query that searches for all posts that have X as a meta/custom field value.
// PSV National Query
if ($_POST['vehicleType'] == 'psv' && $_POST['coverageRegion'] == 'national' ) {
$customkey = 'vehicleType';
$customvalue = $_POST['vehicleType'];
$customkey1 = 'coverageRegion';
$customvalue1 = $_POST['coverageRegion'];
$customkey2 = 'locationType';
$customvalue2 = $_POST['locationType'];
global $wpdb;
$my_posts = $wpdb->get_results("
SELECT $wpdb->posts.*
FROM $wpdb->posts, $wpdb->postmeta, $wpdb->postmeta AS mt1
WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id
AND $wpdb->postmeta.meta_key = '$customkey'
AND $wpdb->postmeta.meta_value = '$customvalue'
AND mt1.meta_key = '$customkey1'
AND mt1.meta_value = '$customvalue1'
AND mt2.meta_key = '$customkey2'
AND mt2.meta_value = '$customvalue2'
AND $wpdb->posts.post_status = 'publish'
AND $wpdb->posts.post_type = 'post'
ORDER BY $wpdb->posts.post_date DESC
");
$args = array(
'meta_query' => array(
array(
'key' => $customkey,
'value' => $customvalue,
'compare' => '='
),
array(
'key' => $customkey1,
'value' => $customvalue1,
'compare' => '='
),
array(
'key' => $customkey2,
'value' => $customvalue2,
'compare' => '='
)
)
);
$query = new WP_Query( $args );
foreach ($query as $post) :
setup_postdata($post);
echo '<div><a href="';
the_permalink();
echo '"></div>';
the_title();
endforeach;
}
Now for my post I have 1 value for each meta key and this works fine, I want to however have multiple values.
For example...
"gas, electricity, water"
When I add multiple values however the query returns null, I presumer its because im saying if...
postmeta.meta_value = '$customvalue'
Can anybody give me advice on where im going wrong?

Answer 1

Why don't you use the built in WP QUERY, it supports meta field array operators.
for example:
$query = new WP_Query( array(
'meta_key' => 'color',
'meta_value' => 'blue',
'meta_compare' => '!='
));
Ref: http://codex.wordpress.org/Class_Reference/WP_Query#Custom_Field_Parameters

Answer 2

If you are using multiple matches in a query's where clause you should use the IN variant istead of the =.
The only row I see in your query where you use $customvalue is here
AND $wpdb->postmeta.meta_value = '$customvalue'
You should change the = to IN and seperate the values with a , and quotes ' ' like this for example
AND $wpdb->postmeta.meta_value IN ('gas','electricity','water')
I ditched the $customvalue in the above code to make the point of the seperator of the IN value.
Hopefully this puts you on the right track.