如何對子查詢中的值求和

我需要從多個表中收集一些值並將這些值作為一列匯總到結果表中。

我的查詢如下所示：

SELECT 
u.ID as id, 
(
   SELECT `meta_value` as user_name FROM `wxe4_usermeta` 
   WHERE `umeta_id` = u.ID AND `meta_key` = 'nickname'
) as user_name,
(
   SELECT SUM(rounds) FROM wxe4_170 WHERE user = u.ID
) as a170_score,
(
   select IF (count(*) > 0, count(*)*66, 0) FROM wxe4_aroundtheworld WHERE user = u.ID
) as atw_score,
(
   select IF (count(*) > 0, count(*)*100, 0) FROM wxe4_X100 WHERE user = u.ID 
) as x100_score,
SUM(a170_score + atw_score + x100_score) as darts_total_thrown
FROM darts.wxe4_users as u

總和引發“錯誤程式碼：1054。‘欄位列表’中的未知列’a170_score’”錯誤。

我得到的沒有總和：

| id | user_name | a170_score | atw_score | x100_score |
--------------------------------------------------------
| 1  | someUser  | 449        | 3102      | 200        |

我對總和的期望：

| id | user_name | a170_score | atw_score | x100_score | darts_total_thrown |
----------------------------------------------------------------------------
| 1  | someUser  | 449        | 3102      | 200        | 3751              |

為什麼我不能訪問這些值以及如何解決這個問題？

您不能以這種方式使用新列。使用子查詢使用數據進行計算

SELECT
wxe4_usern.*,(wxe4_usern.a170_score + wxe4_usern.atw_score + wxe4_usern.x100_score) as darts_total_thrown
FROM
(SELECT 
u.ID as id, 
(
   SELECT `meta_value` as user_name FROM `wxe4_usermeta` 
   WHERE `umeta_id` = u.ID AND `meta_key` = 'nickname'
) as user_name,
(
   SELECT SUM(rounds) FROM wxe4_170 WHERE user = u.ID
) as a170_score,
(
   select IF (count(*) > 0, count(*)*66, 0) FROM wxe4_aroundtheworld WHERE user = u.ID
) as atw_score,
(
   select IF (count(*) > 0, count(*)*100, 0) FROM wxe4_X100 WHERE user = u.ID 
) as x100_score
FROM darts.wxe4_users as u) wxe4_usern

引用自：https://dba.stackexchange.com/questions/269859