Question

我的代码出错了，我会感激一些帮助。这只是我尝试学习的第一天，请尽量保持简单，谢谢

#1064 - You have an error in your SQL syntax; check the manual that 
corresponds to your MariaDB server version for the right syntax to use 
near 'FROM specials LEFT JOIN products_description LEFT JOIN products 
WHERE special' at line 2

SELECT specials.specials_id, specials.products_id,specials_new_products_price, products.products_image,  products.products_price,products.products_image, products.products_quantity,products.products_model,products_description.products_name,products_description.products_description,
FROM specials 
LEFT JOIN  products_description
LEFT JOIN  products
WHERE specials.products_id = products.products_id AND specials.products_id = products_description.products_id AND products.products_quantity>0

Answer 1

检查此语法

SELECT column_name(s)
FROM table1
LEFT JOIN table2
ON table1.column_name=table2.column_name;

实施例

SELECT specials.specials_id, specials.products_id,specials_new_products_price, products.products_image,  products.products_price,products.products_image, products.products_quantity,products.products_model,products_description.products_name,products_description.products_description
FROM specials 
LEFT JOIN  products on specials.products_id = products.products_id
LEFT JOIN  products_description on specials.products_id = products_description.products_id
WHERE products.products_quantity>0

希望这有效

Answer 2

FROM之前的错误逗号

SELECT 
      specials.specials_id
    , specials.products_id
    , specials_new_products_price
    , products.products_image
    , products.products_price
    , products.products_image
    , products.products_quantity
    ,products.products_model
    ,products_description.products_name
    ,products_description.products_description
FROM specials 
LEFT JOIN  products_description on specials.products_id = products_description.products_id
LEFT JOIN  products on specials.products_id = products.products_id
WHERE products.products_quantity>0

Answer 3

当您使用JOIN子句时，您应该使用ON来连接表而不是在哪里。

SELECT specials.specials_id, specials.products_id,specials_new_products_price, products.products_image,  products.products_price,products.products_image, products.products_quantity,products.products_model,products_description.products_name,products_description.products_description,
FROM specials 
LEFT JOIN  **ON** products_description specials.products_id = products_description.products_id
LEFT JOIN  products
**ON** specials.products_id = products.products_id  Where products.products_quantity>0

如何在mysql中使用LEFT JOIN

3 个答案: