php - 追加数据 MySQL 查询两个表

Question

我有两个表：product和url_alias

产品表有两列：product_id和model

url_alias表有两列：product_id和keyword

因此，product_id 是两个表的唯一主键。

现在，如果两个表的product_id相同，我想将product.model的信息添加（附加）到url_alias.keyword 。

例如：

product.product_id = 123
product.model = 987

product.product_id = 123
url_alias.keyword = my-first-book.html

Desired result = 987-my-first-book.html

我该怎么做？

PS：'-'连字符也需要与模型添加。

Answer 1

试试CONCAT::

Select
product.product_id,
CONCAT(product.model,'-', url_alias.keyword)
from 
product 
inner join url_alias on (url_alias.product_id=product.product_id)

Answer 2

SELECT CONCAT(product.model, '-', url_alias.keyword) AS url
FROM product
INNER JOIN url_alias
ON product.product_id = url_alias.product_id
WHERE product.product_id = '123'

Answer 3

    SELECT CONCAT(p.product_id,' - ',u.keyword ) AS res
    FROM product AS p
    LEFT JOIN
    url_alias AS u USING (product_id)
    WHERE p.product_id = 123

注意：如果您想获得所有产品的结果，请删除 WHERE 条件