我可以在同一父查詢中使用子查詢值嗎？

Question

SELECT t.title, ( 
    SELECT AVG(star_rating) 
    FROM reviews r 
    WHERE r.id = t.id ) AS rating  
FROM table_1 t  
WHERE rating >= '4'

PHPMYADMIN顯示錯誤->'where子句'中的未知列'rating'

Answer 1

嘗試這個;

SELECT t.title, 
       (SELECT AVG(star_rating) 
        FROM reviews r 
        WHERE r.id = t.id ) AS rating 
FROM table_1 t 
WHERE (SELECT AVG(star_rating) 
       FROM reviews r 
       WHERE r.id = t.id ) >= 4