get_userdata and get_user_field_by

[markuscode]

Hi last time I ask about the get_user_field, on the ticket #44392.
I ask not about usermeta, I ask about users table. How can get just user_email by user ID without selecting all information, just user_email.

Always I do for myself something like that:

<?php
if(!function_exists('get_user_field_by')){

        /**
         * Gets the user field by.
         *
         * @param      string  $fuild  The fuild
         * @param      array   $where  The where
         */
        function get_user_field_by($fuild = "",$where = array()){
                global $wpdb;
                $sql = "SELECT ".$fuild." FROM {$wpdb->prefix}users";
                $wherecount = 0;
                foreach ($where as $key => $value) {
                        if($wherecount == 0){
                                $sql .= " WHERE $key = '$value'";
                        }else{
                                $sql .= " AND $key = '$value'";
                        }
                }
                $wherecount++;
                $results = $wpdb->get_results( $sql , OBJECT );
                if(!empty($results)){
                        $results = reset($results);
                }
                return $results;
        }
        
}

[swissspidy]

Hey there

No need to create a new ticket for that, a comment on #44392 would suffice.

That being said, a function like get_user_field_by probably has no use case in core or in many plugins either.

Even if you only need the user's email address I'd highly recommend you to use get_userdata(). Fetching a user this way will try to avoid querying the database directly when the user has already been requested before and is available either in memory or in the object cache.