Question

假设我们有3个表：产品，属性和详细信息。

产品

id name price
1  pr1  120
2  pr2  140
3  pr3  200
4  pr4  165

属性

id name
1  color
2  guarantee
3  resolution
4  year
5  contrast ratio

详情

id productId attributeId value
1  1         1           grey
2  1         2           yes
3  2         1           black
4  2         4           2011
5  2         5           70 000:1
6  4         2           no

并希望例如选择color = black，year = 2011和对比度= 70 000：1的所有产品。在这个例子中，结果将是id = 2的产品。那将是什么mysql语法？

SELECT * FROM products, details WHERE products.id = details.productId
AND details.attributeId = 1 (For the first attribute)
AND details.attributeId = 4 (For the second and third attribute?)
...

Answer 1

使用

SELECT * 
FROM products p 
INNER JOIN (SELECT * FROM details d WHERE d.attributeId = 1 ) d1 ON p.ID = d1.productid 
INNER JOIN (SELECT * FROM details d WHERE d.attributeId = 4 ) d4 ON p.ID = d4.productid 
INNER JOIN (SELECT * FROM details d WHERE d.attributeId = 5 ) d5 ON p.ID = d5.productid 
WHERE 
d1.value = 'black' AND
d4.value = '2011' AND
d5.value = '70 000:1'

选择具有特定属性

1 个答案: