Question

我有2个表，产品和类别定义如下：

表：类别 - category_id，类别

表：产品 - product_id，category_id，item_no，description

我正在尝试将描述和类别连接到一个可搜索的字段中。当我执行以下操作时，它可以工作，但是代码很笨重：

SELECT *, concat(description, ' ',category) as searchable 
FROM products, categories 
where concat(description, ' ',category) like '%flowers%' 
and concat(description, ' ',category) like '%rainbow%' 
and products.category_id=categories.category_id order by products.category_id

所以我正在尝试编写一个像这样的子查询：

SELECT *
FROM products, categories, 
(SELECT concat(description, ' ',category) as searchable 
FROM products, categories 
where products.category_id=categories.category_id 
group by product_id) as sub
where searchable like '%flowers%' and searchable like '%rainbow%' 
and products.category_id=categories.category_id order by products.category_id;

此查询为每个product_id返回多个不正确的结果，当我尝试按product_id分组时，每个结果都会显示不正确的可搜索字段。

任何帮助都将不胜感激。

Answer 1

有时关键是要简化。以下内容将查找具有与'％rainbow％'匹配的描述或类别的产品。

通过将查询分解为两个LIKE子句，我们还通过消除繁重的CONCAT操作来提高性能。

SELECT p.*
FROM products AS p 
LEFT JOIN categories AS c ON p.category_id = c.category_id 
WHERE p.description LIKE '%rainbow%'
    OR c.category LIKE '%rainbow%'
GROUP BY p.product_id

Mysql concat并在多个表上搜索

1 个答案: