详解MySQL中JSON数据类型用法及与传统JSON字符串对比

-- 创建包含JSON字段的表
CREATE TABLE products (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100),
    attributes JSON,
    json_string TEXT
);

-- 插入JSON数据
INSERT INTO products (name, attributes, json_string) VALUES (
    'Laptop',
    '{"brand": "Dell", "specs": {"cpu": "i7", "ram": "16GB"}, "tags": ["electronics", "computer"]}',
    '{"brand": "Dell", "specs": {"cpu": "i7", "ram": "16GB"}, "tags": ["electronics", "computer"]}'
);

-- 查询品牌为Dell的产品（传统JSON字符串方式）
SELECT * FROM products WHERE json_string LIKE '%"brand": "Dell"%';

-- 查询品牌为Dell的产品（JSON数据类型方式）
SELECT * FROM products WHERE JSON_EXTRACT(attributes, '$.brand') = 'Dell';
-- 或使用箭头语法（MySQL 8.0+）
SELECT * FROM products WHERE attributes->'$.brand' = '"Dell"';

-- 为JSON字段的brand属性创建索引
ALTER TABLE products ADD COLUMN brand VARCHAR(50) 
    GENERATED ALWAYS AS (JSON_UNQUOTE(attributes->'$.brand')) STORED;
CREATE INDEX idx_brand ON products(brand);

{
  "brand": "Dell",
  "specs": {
    "cpu": "i7",
    "ram": "16GB"
  }
}

{
  "tags": ["electronics", "computer", "laptop"]
}

SELECT * FROM products WHERE JSON_CONTAINS(attributes->'$.tags', '"electronics"');