SELECT
m.user_id,
DATE(STR_TO_DATE(CONCAT(um1.meta_value, '-', um2.meta_value, '-', um3.meta_value), '%Y-%m-%d')) AS DateEXP,
IFNULL(um5.meta_value, 0) AS vID
FROM
wp_usermeta m
    INNER JOIN wp_usermeta um1 ON m.user_id = um1.user_id AND um1.meta_key = 'year'
    INNER JOIN wp_usermeta um2 ON m.user_id = um2.user_id AND um2.meta_key = 'month'
    INNER JOIN wp_usermeta um3 ON m.user_id = um3.user_id AND um3.meta_key = 'day'
    LEFT JOIN wp_usermeta um5 ON m.user_id = um5.user_id AND um5.meta_key = 'vID'
WHERE
STR_TO_DATE(CONCAT(um1.meta_value, '-', um2.meta_value, '-', um3.meta_value),'%Y-%m-%d') BETWEEN '2017-07-01' AND '2017-07-31'
GROUP BY m.user_id