sql join三个表的查询问题

Question

我是mysql的新手。这里是我的db表的结构。*我怎样才能加入所有三个表，使结果看起来像第四个表？

表产品

id  name category user_id 
1  abc  2    1 
2  syz  3    1 

表格类别

id  name 
1  aaa 
2  bbb 
3  ccc 

表product_image

id  image  product_id 
1  abc.jpg   1 
2  xyz.jpg   1 

第四表结果看起来像

id  name  category_name   image 
1  abc  aaa     xyz.jpg 

请帮我解决这个问题。我试过但没有得到正确的结果。

SELECT product. * , categories.name AS cat_name, product_image.image AS product_image 
FROM `product` 
INNER JOIN categories ON categories.id = product.category and `user_id`='1' 
INNER JOIN `product_image` ON product_image.product_id = product.id 
ORDER BY rand() 
LIMIT 1 

编辑零件

我们需要product_image一个图像这是在按照相关的多个图像的product_id

Answer 1

SELECT 
    p.id, p.name, p.category, p.user_id, 
    c.id, c.name as cat_name, 
    prod_image.image as product_image 
FROM 
    Product p, 
    Categories c, 
    product_image prod_image 
WHERE 
    p.user_id=1 
AND 
    p.category=c.id 
AND 
    prod_image.product_id=p.id 
ORDER BY rand() LIMIT 1 

Answer 2

试试这个

SELECT product.name , categories.name AS cat_name, product_image.image AS product_image 
FROM `product` 
JOIN categories ON (categories.id = product.category) 
JOIN `product_image` ON product_image.product_id = product.id Where product.`user_id`='1' 
ORDER BY rand() 
LIMIT 1 

Answer 3

SELECT Product.id as Id,Product.name as name, Categories.name as category_name ,product_image.image as image 
FROM 
Product, Categories,product_image 
WHERE 
Product.ID='1' AND Categories.Id='1' AND product_image='1' 

Answer 4

试试这个

SELECT p.id, p.name , c.name as category_name, i.image FROM Product AS p 

INNER JOIN Categories as c 

ON c.id=p.category LEFT JOIN 

(SELECT image, product_id FROM product_image ORDER BY RAND() LIMIT 1 ) AS i ON i.product_id=p.id WHERE p.id=1