Using WP_Query to Return Custom Search Results

Hey all,

I have created a search box with a drop down box of 4 options to customize the search:

• A general default search, no filter
• A custom search according to the post title for a custom post type only.
• A custom search according to the post content for a custom post type only.
• A custom search according to the meta value attached to a post for a custom post type only.

I’ve built the search box to handle this. It looks like this in the functions.php file:

` function r3_search_form( $form ) {
$form = ‘<form role=”search” method=”get” id=”top_nav_search” action=”‘ . home_url( ‘/’ ) . ‘” >
<div>

<label class=”screen-reader-text” for=”type”>’ . __(‘Type of Search:’) . ‘</label>
<select name=”type” id=”ic_search_type” >
<option value=”all”>General Search |search full site contents|</option>
<option value=”name”>Mineral Name |search the approved name for the mineral|</option>
<option value=”loc”>Locality |search by mine name, district, state, or country|</option>
<option value=”detail”>Description |search the description of the mineral|</option>
</select>
<label class=”screen-reader-text” for=”s”>’ . __(‘Search Form:’) . ‘</label>
<input type=”text” value=”‘ . get_search_query() . ‘” name=”s” id=”s” />
<input type=”submit” id=”searchsubmit” value=”‘. esc_attr__(‘Search’) .'” />
</div>
</form>’;

return $form;
}

add_filter( ‘get_search_form’, ‘r3_search_form’ );`

Using that search box returns a URL with a query string at the end that looks like this: ?type=loc&s=Arizona . You’ll notice that I’ve only added one additional parameter type from what a default search would return.

Here’s what I’m trying do to. Depending on the search result, I need to alter the main query to behave something like one of the following MySQL queries:

1. SELECT * FROM wp_posts,wp_postmeta WHERE wp_posts.ID =
   wp_postmeta.post_id AND wp_postmeta.meta_key = ‘_custom_meta_key’
   AND wp_postmeta.meta_value LIKE ‘%$search_term%’ AND
   wp_posts.post_type = ‘custom-post-type’ ORDER BY wp_posts.post_date
   DESC
2. SELECT * FROM wp_posts WHERE wp_posts.post_title LIKE
   ‘%$search_term%’ AND wp_posts.post_type = ‘custom-post-type’ ORDER
   BY wp_posts.post_date DESC

I’ve found this post from two years ago: http://wordpress.org/support/topic/query-posts-by-custom-fields-value

This comes pretty close to what I’m wanting to accomplish, but my question is if there is a way to do this within the WP_Query loop exclusively without using the WP database class ($wpdb).

I’ve set up a pre-get-post filter function with a switch according to the type parameter in the functions.php file to handle this request, but I am not able to get the query to run as described above using just WP_Query class. Can it be done? Thanks.