MySQL的：問題與左連接

Question

我有以下查詢：

SELECT c.`entity_id`,c. p.`name` as parent_id, c.`name` 
    FROM category c 
    LEFT JOIN category p WHERE c.`parent_id = p.id 
    WHERE c.is_active = 1 
    ORDER BY c.parent_id ASC, c.position ASC; 

，但我得到的第一個WHERE子句，任何人都可以找到這個錯誤在這裏的錯誤？謝謝

Answer 1

您已添加where子句兩次。試試如下：

SELECT c.`entity_id`,c. p.`name` as parent_id, c.`name` 
FROM category c 
    LEFT JOIN category p on c.`parent_id = p.id 
    Where c.is_active = 1 
    ORDER BY c.parent_id ASC, c.position ASC;