如何合併這個mySQL查詢

Question

什麼應該是合併下面的mySQL查詢的最佳方式？它應該複雜嗎？我想通過match_score對結果進行排序，就像在第一個查詢中一樣。我聽說有一個聯合選項可以加入多個select查詢，但不確定它是如何工作的，但是在一個select查詢下沒有辦法合併3個查詢嗎？謝謝你的時間。

查詢1：

SELECT 
    ui.User_ID, 
    TRUNCATE(COUNT(*)/2, 1) + COUNT(my.interest_id) * 2.5 AS match_score 
FROM 
    User_Interests ui 
     LEFT JOIN 
    User_Interests my ON (my.user_id = ? 
     AND my.interest_id = ui.interest_id) 
GROUP BY ui.user_id 
ORDER BY match_score DESC 

問題2：

SELECT 
    ud.User_ID, 
    TRUNCATE(COUNT(*)/2, 1) + COUNT(my.dislike_id) * 2.5 AS match_score 
FROM 
    User_Dislikes ud 
     LEFT JOIN 
    User_Dislikes my ON (my.user_id = ? 
     AND my.dislike_id = ud.dislike_id) 
GROUP BY ud.user_id 
ORDER BY match_score DESC 

問題3：

SELECT 
    u.* 
FROM 
    User u 
     LEFT JOIN 
    User_Status us ON u.id = User_ID1 AND us.User_ID2 = 5 
WHERE 
    gender = ? 
     AND (us.Status != 'FRIENDS' 
     OR us.status IS NULL) 
     AND u.birthday >= DATE(NOW()) - INTERVAL ? YEAR - INTERVAL 1 YEAR 
     AND u.birthday < DATE(NOW()) - INTERVAL ? YEAR 

Answer 1

你說你想添加分數。好的。您也可以說查詢3用於過濾，但由於外部聯接不會自然過濾任何內容，因此唯一的過濾器就是性別和出生日期。但是，似乎您正嘗試使用用戶5篩選非朋友。我想你正在尋找這樣的東西：

select 
    u.*, 
    i.match_score as interests_match_score, 
    d.match_score as dislikes_match_score, 
    coalesce(i.match_score, 0) + coalesce(d.match_score, 0) as total_match_score 
from user u 
left join 
(
    select 
    ui.user_id, 
    truncate(count(*)/2, 1) + count(my.interest_id) * 2.5 as match_score 
    from user_interests ui 
    left join user_interests my on (my.user_id = ? and my.interest_id = ui.interest_id) 
    group by ui.user_id 
) i on i.user_id = u.id 
left join 
(
    select 
    ud.user_id, 
    truncate(count(*)/2, 1) + count(my.dislike_id) * 2.5 as match_score 
    from user_dislikes ud 
    left join user_dislikes my on (my.user_id = ? and my.dislike_id = ud.dislike_id) 
    group by ud.user_id 
) d on d.user_id = u.id 
where id in (select user_id1 from user_status where user_id2 = 5 and status <> 'friends') 
and gender = ? 
and u.birthday >= date(now()) - interval ? year - interval 1 year 
and u.birthday < date(now()) - interval ? year; 

您可能必須作出修改，但這些應該很容易。

Answer 2

聯盟是聚體的最佳方式ge多個查詢在同一時間。下面是這樣做的方式

SELECT 
    User_ID, 
    TRUNCATE(COUNT(*)/2, 1) + COUNT(interest_id) * 2.5 AS match_score from { 

    SELECT 
    ui.User_ID, 
    TRUNCATE(COUNT(*)/2, 1) + COUNT(my.interest_id) * 2.5 AS match_score 
FROM 
    User_Interests ui 
     LEFT JOIN 
    User_Interests my ON (my.user_id = ? 
     AND my.interest_id = ui.interest_id) 

     union 

     SELECT 
    ud.User_ID, 
    TRUNCATE(COUNT(*)/2, 1) + COUNT(my.dislike_id) * 2.5 AS match_score 
FROM 
    User_Dislikes ud 
     LEFT JOIN 
    User_Dislikes my ON (my.user_id = ? 
     AND my.dislike_id = ud.dislike_id) 

     union 


     SELECT 
    ud.User_ID, 
    TRUNCATE(COUNT(*)/2, 1) + COUNT(my.dislike_id) * 2.5 AS match_score 
FROM 
    User u 
     LEFT JOIN 
    User_Status us ON u.id = User_ID1 AND us.User_ID2 = 5 
WHERE 
    gender = ? 
     AND (us.Status != 'FRIENDS' 
     OR us.status IS NULL) 
     AND u.birthday >= DATE(NOW()) - INTERVAL ? YEAR - INTERVAL 1 YEAR 
     AND u.birthday < DATE(NOW()) - INTERVAL ? YEAR 

} results 

GROUP BY User_ID 
ORDER BY match_score DESC