MySQL/MariaDB - 查询通过引用 table 在 table 中搜索

Question

我目前有三个 table：

    desc products;
+----------------+-------------------+------+-----+---------+----------------+
| Field          | Type              | Null | Key | Default | Extra          |
+----------------+-------------------+------+-----+---------+----------------+
| id             | int(255) unsigned | NO   | PRI | NULL    | auto_increment |
| name           | text              | NO   |     | NULL    |                |
| desc_short     | text              | NO   |     | NULL    |                |
+----------------+-------------------+------+-----+---------+----------------+

desc tags;
+------------+-------------------+------+-----+---------+----------------+
| Field      | Type              | Null | Key | Default | Extra          |
+------------+-------------------+------+-----+---------+----------------+
| id         | int(255) unsigned | NO   | PRI | NULL    | auto_increment |
| tag        | varchar(255)      | YES  | UNI | NULL    |                |
| iscategory | tinyint(4)        | NO   |     | 0       |                |
+------------+-------------------+------+-----+---------+----------------+

desc products_tags;
+------------+-------------------+------+-----+---------+-------+
| Field      | Type              | Null | Key | Default | Extra |
+------------+-------------------+------+-----+---------+-------+
| product_id | int(255) unsigned | YES  | MUL | NULL    |       |
| tag_id     | int(255) unsigned | YES  | MUL | NULL    |       |
+------------+-------------------+------+-----+---------+-------+

products_tags 实际上是一个引用 table，我用以下方法创建的：

CREATE TABLE product_tags (
    product_id INT(255) UNSIGNED, 
    tag_id INT(255) UNSIGNED, 
    CONSTRAINT fk_products_id FOREIGN KEY (tag_id)  REFERENCES tags(id)  ON DELETE CASCADE ON UPDATE CASCADE, 
    CONSTRAINT fk_tag_id   FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE CASCADE ON UPDATE CASCADE
);

我正在尝试通过搜索相应的标签来过滤 table 产品中的项目。我已经找到了一些 similar problems 但我无法让它正常工作....

非常感谢。

Answer 1

试试这个连接查询：

SELECT p.id, p.name, p.desc_short
FROM products p
INNER JOIN products_tag pt
    ON p.id = pt.product_id
INNER JOIN tags t
    ON t.id = pt.tag_id
WHERE t.tag = 'some tag'

MySQL/MariaDB - 查询通过引用 table 在 table 中搜索

MySQL/MariaDB - query Searching in table via a reference table

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foreign-keys

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