如何在嵌套集中按类别名称获取产品列表

Question

我有以下 sql 嵌套集，我需要显示电子产品类别及其子类别下的所有产品

电子产品 -> 便携式电子产品 -> mp3 播放器 -> 闪光灯

在 mysql

中执行此操作的 sql 查询应该是什么

--
-- Table structure for table `categories`
--

CREATE TABLE IF NOT EXISTS `categories` (
  `category_id` int(11) NOT NULL,
  `name` varchar(20) NOT NULL,
  `left_node` int(11) NOT NULL,
  `right_node` int(11) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;

--
-- Dumping data for table `categories`
--

INSERT INTO `categories` (`category_id`, `name`, `left_node`, `right_node`) VALUES
(1, 'electronics', 1, 20),
(2, 'televisions', 2, 9),
(3, 'tube', 3, 4),
(4, 'lcd', 5, 6),
(5, 'plasma', 7, 8),
(6, 'portable electronics', 10, 19),
(7, 'mp3 players', 11, 14),
(8, 'flash', 12, 13),
(9, 'cd players', 15, 16),
(10, '2 way radios', 17, 18);

-- --------------------------------------------------------

--
-- Table structure for table `products`
--

CREATE TABLE IF NOT EXISTS `products` (
  `product_id` int(11) NOT NULL,
  `name` varchar(40) DEFAULT NULL,
  `cat_id` int(11) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;

--
-- Dumping data for table `products`
--

INSERT INTO `products` (`product_id`, `name`, `cat_id`) VALUES
(1, '20" TV', 3),
(2, '36" TV', 3),
(3, 'Super-LCD 42"', 4),
(4, 'Ultra-Plasma 62"', 5),
(5, 'Value Plasma 38"', 5),
(6, 'Power-MP3 5gb', 7),
(7, 'Ipod 4gb', 8),
(8, 'Porta CD', 9),
(9, 'Walkman', 9),
(10, 'Family Talk 360', 10);

-- --------------------------------------------------------

--
-- Table structure for table `product_categories`
--

CREATE TABLE IF NOT EXISTS `product_categories` (
  `product_id` int(11) NOT NULL,
  `category_id` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

--
-- Dumping data for table `product_categories`
--

INSERT INTO `product_categories` (`product_id`, `category_id`) VALUES
(1, 3),
(2, 3),
(3, 4),
(4, 5),
(5, 5),
(6, 7),
(7, 8),
(8, 9),
(9, 9),
(10, 10);

Answer 1

SELECT p.* FROM product p,categories c WHERE p.category_id = c.category_id and p.category_id = 1

Answer 2

您可以使用 INNER JOIN 来获取您想要的行。

SELECT categories.name, products.name
FROM categories
INNER JOIN products ON categories.category_id = products.category_id
WHERE categories.category_id = ?

Answer 3

SELECT c.name, c.category_id, c.left_node, c.right_node, p.product_id, p.name
from categories c, products p
where c.category_id = p.category_id group by c.category_id

如何在嵌套集中按类别名称获取产品列表

how to get products list by category name in nested set

php

mysql

nested

set