Как объединить 2 запроса SELECT, когда один из запросов унифицирован

Question

Я хочу присоединиться к 2 выборам один:

SELECT user_email FROM users WHERE user_id = ?

И другой выбор:

SELECT f.friends_friend AS user_id, 
       users.username AS friend_name, 
       users.user_avtr AS profile_pic
FROM friends as f
LEFT OUTER JOIN(
    SELECT user_id,username,users.user_avtr FROM users
)AS users
ON f.friends_friend = users.user_id
WHERE f.friends_member = ?
UNION
SELECT f.friends_member AS user_id, 
       users.username AS friend_name, 
       users.user_avtr AS profile_pic
FROM friends as f
LEFT OUTER JOIN(
    SELECT user_id,username,users.user_avtr 
    FROM users
)AS users
ON f.friends_member = users.user_id
WHERE f.friends_friend = ?

Я хочу выполнить эти 2 запроса в одном запросе

Answer 1

Может быть, я неправильно понимаю ваш вопрос, но почему вы не можете просто сделать это?

SELECT f.friends_friend AS user_id, 
       users.username AS friend_name, users.user_email as user_email,
       users.user_avtr AS profile_pic
FROM friends as f
LEFT OUTER JOIN(
    SELECT user_email, user_id,username,users.user_avtr FROM users
)AS users
ON f.friends_friend = users.user_id
WHERE f.friends_member = ?
UNION
SELECT f.friends_member AS user_id, 
       users.username AS friend_name, users.user_email as user_email,
       users.user_avtr AS profile_pic
FROM friends as f
LEFT OUTER JOIN(
    SELECT user_email, user_id,username,users.user_avtr 
    FROM users
)AS users
ON f.friends_member = users.user_id
WHERE f.friends_friend = ?