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// 定义价格服务接口

interface PriceService {

getPrice(id: string): Promise;

updatePrice(id: string, price: number): Promise;

}

// 实现价格服务

class PriceServiceImpl implements PriceService {

private prices: Map = new Map();

constructor() {

this.prices.set('basic', 9.99);

this.prices.set('pro', 19.99);

}

getPrice(id: string): Promise {

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return Promise.resolve(this.prices.get(id));

}

updatePrice(id: string, price: number): Promise {

this.prices.set(id, price);

return Promise.resolve();

}

}

]]>

-- 插入价格信息

INSERT INTO prices (id, price) VALUES ('basic', 9.99);

-- 查询价格信息

SELECT price FROM prices WHERE id = 'basic';

]]>