使用Node.js和PostgreSQL构建数据库应用

npm init -y
npm install pg

import { Pool } from 'pg'

const pool = new Pool({
    host: 'localhost',
    port: 5432,
    database: 'demo',
    user: 'postgres',
    password: '123456',
})

// 查询所有用户
const res = await client.query('select * from "user"')
const list = res.rows
console.log('查询结果', list)

// 插入新用户
await client.query(
  'insert into "user" (user_id, username, password, status) values ($1, $2, $3, $4)',
  [2, '张三', '123456', false]
)

// 更新用户信息
await client.query(
  'update "user" set username = $1 where user_id = $2', 
  ['张三2', 2]
)

// 删除用户
await client.query(
  'delete from "user" where user_id = $1', 
  [2]
)

import { Pool } from 'pg'

const pool = new Pool({
    host: 'localhost',
    port: 5432,
    database: 'demo',
    user: 'postgres',
    password: 'your_secure_password', // 实际应用中应从环境变量读取
})

let client = null

const run = async () => {
    try {
        // 从连接池获取客户端
        client = await pool.connect()

        // 执行各种数据库操作
        // 查询示例
        const res = await client.query('SELECT * FROM "user"')
        console.log('查询结果:', res.rows)
        
        // 在实际应用中，可以在这里添加更多操作
        
    } catch (err) {
        console.error('数据库操作失败', err)
    } finally {
        // 释放客户端回连接池
        if (client) {
            client.release()
        }
        // 关闭连接池
        await pool.end()
    }
}

run()