wpdb::get_results() │ public │ WP 0.71

Gets all data of the specified query (all rows and columns). The result is returned as an array. Each element of the array is an object with data of a separate row of the table.

Method of the class: wpdb{}

No Hooks.

Returns

array|null. The result of the database query. Will return:

• Array of objects — when $output = OBJECT or OBJECT_K.
• Array of arrays — when $output = ARRAY_A or ARRAY_N.
• [] — when no rows are found for the query or there is a query error.
• NULL — when the query is an empty string or an incorrect output type ($output_type is passed).

Usage

global $wpdb;
$wpdb->get_results( $query, $output );

$query(string)

The query to be executed.

This parameter can be set to null, then the function will return the result of the last query that was executed.

Default: null

$output(constant/string)

A flag indicating in what form the data should be returned. There are 4 options:

• OBJECT — will return an array of objects with numeric keys - the elements of the array will be objects of the table rows — [ 0 => object ].
• OBJECT_K — similar to the previous one, only the indices of the main array will be the values of the first column of the query result — [ 'field' => object ].
  Note that if the same values enter the index, the data will be overwritten.
• ARRAY_N — will return a numeric array, each element of which will also be a numeric array — [ 0 => [...] ].
• ARRAY_A — will return a numeric array, each element of which will be an associative array, where the key will be the column name — [ 'field' => [...] ].

Default: OBJECT

Examples

#1 Display the links to the author's drafts with ID = 5

<?php
$fivesdrafts = $wpdb->get_results(
	"SELECT * FROM $wpdb->posts WHERE post_status = 'draft' AND post_author = 5"
);

if( $fivesdrafts ) :
	foreach( $fivesdrafts as $post ){
		setup_postdata($post);
		?>
			<h2><a href="<?php the_permalink(); ?>" rel="bookmark"
				title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h2>
		<?php
	}
	else :
	?>
	<h2> Not found</h2>
	<?php
endif;
?>

#2 Get the IDs and titles of drafts whose author ID = 5 and display the posts titles

$fivesdrafts = $wpdb->get_results(
	"SELECT ID, post_title FROM $wpdb->posts WHERE post_status = 'draft' AND post_author = 5"
);

foreach ( $fivesdrafts as $fivesdraft ) {
	echo $fivesdraft->post_title;
}

#3 Example of a complex query with GROUP BY (reviews in WooCommerce)

/**
* Returns the results of the rating (reviews in WooCommerce) grouped by ratings
*
* @param int $post_id post ID
*
* @return array of objects, where each object is a lumped data on one of the grades
*/
function get_cnt_rating_reviews_one_product( $post_id ){
	global $wpdb;

	return $wpdb->get_results( $wpdb->prepare(
		"
		SELECT COUNT(meta.meta_id) as num, meta.meta_value
		FROM $wpdb->comments as comments
		INNER JOIN $wpdb->commentmeta as meta ON comments.comment_ID = meta.comment_id
		WHERE comments.comment_post_ID = %d AND meta_key = 'rating'
		GROUP BY meta.meta_value;
		",
		$post_id
	) );

}

// usage
get_cnt_rating_reviews_one_product( 4350 );

#4 Error handling

This is how to intercept errors from get_results():

global $wpdb;
$result = $wpdb->get_results( "SELECT * FROM invalid query" );

if ( $wpdb->last_error ) {
  echo 'wpdb error: ' . $wpdb->last_error;
}