node_util/index/db.js

const { Pool } = require('pg');

class Database {
    constructor(config) {
        this.pool = new Pool(config);
    }

    async connect() {
        this.client = await this.pool.connect();
        return this.client;
    }

    async setSchema(schema) {
        if (this.client) {
            await this.client.query(`SET search_path TO ${schema}`);
        } else {
            throw new Error('Client is not connected.');
        }
    }

    async query(text, params) {
        if (this.client) {
            return this.client.query(text, params);
        } else {
            throw new Error('Client is not connected.');
        }
    }

    async disconnect() {
        if (this.client) {
            this.client.release();
            this.client = null;
        }
    }
}

// 导出数据库实例
module.exports = Database;