sql聯接查詢問題與三個表

Question

我是mysql的新手。這是我的db表的結構。*如何將所有三個表連接起來以得到類似於第四個表的結果？

餐桌產品

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

表類別

id      name
1       aaa
2       bbb
3       ccc

表product_image

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

第四表結果看起來像

id      name      category_name           image
 1      abc       aaa                    xyz.jpg

請幫我解決這個問題。 我嘗試過，但是沒有得到正確的結果。

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

編輯部

我們需要product_image中的一幅圖像，根據product_id將其關聯到多幅圖像

Answer 1

試試這個

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

Answer 2

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 3

嘗試這個

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 4

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'