mysql - 如何从两个表中获取所有数据？

Question

我有两张桌子

1.产品

prod_id   prod_name
   1       honda
   2       hero
   3       marcedes
   4       audi

2.产品分类

cat_id  prod_id
  1         1
  1         2
  2         3
  2         4

现在我想要如下结果

prod_id    prod_name    cat_id
   1         honda        1
   2         hero         1
   3         marcedes     2
   4         audi         2

我似乎无法弄清楚这一点。非常感谢任何帮助！

score 5 · Accepted Answer

select products.*, category.cat_id 
from products, category 
where products.prod_id = category.prod_id

score 2 · Accepted Answer

select products.prod_id ,products.prod_name, category.cat_id 
from products, category 
where category.prod_id  = products.prod_id

score 2 · Accepted Answer

select p.prod_id,p.prod_name,c.cat_id 
from Products p inner join category c 
on p.prod_id = c.prod_id

score 0 · Accepted Answer

只需使用连接，如果您只希望产品具有 cat_id，则更LEFT JOIN改为INNER JOIN.

SELECT t1.prod_id, t1.prod_name, t2.cat_id
FORM Products t1
LEFT JOIN ProductToCategory t2 ON t1.prod_id = t2.prod_id

score 0 · Accepted Answer

select p.prod_id, p.prod_name,c.catid
from products p
inner join prodtocat pc on p.prod_id = pc.prod_id

5 回答 5