WordPress - Query user meta

query-user-meta-table.php

<?php
/**
 * Query user meta table
 *
 * @param string|array $name_patt Meta key pattern match
 * @param string $query_suffix SQL query suffix
 *
 * @return array|null Results of query
 */
function shramee_query_user_meta_table( $name_patt, $query_suffix = '' ) {
	/** @var wpdb $wpdb */
	global $wpdb;

	$select = '`meta_key` as `key`, `meta_value` as `value`, `user_id` as `id`';
	
	// Escape for sql query
	$name_patt = esc_sql( $name_patt );

	if ( is_array( $name_patt ) ) {
		$name_patt = implode( "' OR `meta_key` LIKE '", $name_patt );
	}

	return $wpdb->get_results(
		"SELECT {$select} FROM {$wpdb->usermeta} " .
		"WHERE ( `meta_key` LIKE '{$name_patt}' ) " .
		$query_suffix
	);
}

P.S. https://gist.github.com/shramee/127b8bd42008499a1b327d7f8b0f8419#file-query-meta-php to have single function for both post and user meta.