Postgresql 如何通过Node.js连接到Postgres_Postgresql_Node.js

Postgresql 如何通过Node.js连接到Postgres

postgresql node.js

Postgresql 如何通过Node.js连接到Postgres,postgresql,node.js,Postgresql,Node.js,我发现自己正在尝试创建一个postgres数据库，所以我安装了postgres，并用initdb/usr/local/pgsql/data启动了一个服务器，然后用postgres-D/usr/local/pgsql/data启动了该实例，现在我如何通过节点与之交互？例如，connectionstring是什么，或者我如何才能找到它是什么下面是一个将node.js连接到Postgres数据库的示例我在node.js中使用的接口可以在这里找到更新：-现在已弃用query.on函数，因此上述代码

我发现自己正在尝试创建一个postgres数据库，所以我安装了postgres，并用

initdb/usr/local/pgsql/data

启动了一个服务器，然后用

postgres-D/usr/local/pgsql/data

启动了该实例，现在我如何通过节点与之交互？例如，

connectionstring

是什么，或者我如何才能找到它是什么

下面是一个将node.js连接到Postgres数据库的示例

我在node.js中使用的接口可以在这里找到

更新：-现在已弃用

query.on

函数，因此上述代码将无法正常工作。为了解决这个问题，请看：-

只需添加一个不同的选项-我使用连接到PG，但这也是由于能够与MySQL和sqlite通信。节点DBI还包括构建select语句的功能，这对于动态工作非常方便

快速示例（使用另一个文件中存储的配置信息）：

config.js：

var config = {
  db:{
    host:"plop",
    database:"musicbrainz",
    username:"musicbrainz",
    password:"musicbrainz"
  },
}
module.exports = config;

一种现代而简单的方法：

另请参见：.

一个解决方案可以使用

池

客户端，如下所示：

const { Pool } = require('pg');
var config = {
    user: 'foo', 
    database: 'my_db', 
    password: 'secret', 
    host: 'localhost', 
    port: 5432, 
    max: 10, // max number of clients in the pool
    idleTimeoutMillis: 30000
};
const pool = new Pool(config);
pool.on('error', function (err, client) {
    console.error('idle client error', err.message, err.stack);
});
pool.query('SELECT $1::int AS number', ['2'], function(err, res) {
    if(err) {
        return console.error('error running query', err);
    }
    console.log('number:', res.rows[0].number);
});

您可以查看更多详细信息。

是Kuberchaun和Vitaly提出的答案的替代方案

斯洛尼克工具；您创建了一个连接池，并为您处理连接打开/处理

import {
  createPool,
  sql
} from 'slonik';

const pool = createPool('postgres://user:password@host:port/database');

return pool.connect((connection) => {
  // You are now connected to the database.
  return connection.query(sql`SELECT foo()`);
})
  .then(() => {
    // You are no longer connected to the database.
  });

postgres://user:password@host:port/database

是您的连接字符串（或更规范的连接URI或DSN）

这种方法的好处是，您的脚本确保您不会意外地离开挂起的连接

使用Slonik的其他好处包括：

注意：

pg_connection.js

const PgConnection = require('postgresql-easy');
const dbConfig = require('./config/db');
const pg = new PgConnection(dbConfig);
module.exports = pg;

module.exports =  {
  database: 'your db',
  host: 'your host',
  port: 'your port',
  user: 'your user',
  password: 'your pwd',
}

  const pg_conctn = require('./pg_connection');

  pg_conctn.getAll('your table')
    .then(res => {
         doResponseHandlingstuff();
      })
    .catch(e => {
         doErrorHandlingStuff()     
      })

/config/db.js

const PgConnection = require('postgresql-easy');
const dbConfig = require('./config/db');
const pg = new PgConnection(dbConfig);
module.exports = pg;

module.exports =  {
  database: 'your db',
  host: 'your host',
  port: 'your port',
  user: 'your user',
  password: 'your pwd',
}

  const pg_conctn = require('./pg_connection');

  pg_conctn.getAll('your table')
    .then(res => {
         doResponseHandlingstuff();
      })
    .catch(e => {
         doErrorHandlingStuff()     
      })

你的_handler.js

const PgConnection = require('postgresql-easy');
const dbConfig = require('./config/db');
const pg = new PgConnection(dbConfig);
module.exports = pg;

module.exports =  {
  database: 'your db',
  host: 'your host',
  port: 'your port',
  user: 'your user',
  password: 'your pwd',
}

  const pg_conctn = require('./pg_connection');

  pg_conctn.getAll('your table')
    .then(res => {
         doResponseHandlingstuff();
      })
    .catch(e => {
         doErrorHandlingStuff()     
      })

postgres://[user[:password]@][host][:port][/dbname]

[…]

postgres://localhost
postgres://localhost:5432
postgres://localhost/mydb
postgres://user@localhost
postgres://user:secret_password@localhost

postgres://localhost

postgres://pg@本地主机

postgres://postgres@本地主机

npx@databases/pg test start

pg test

@databases/pg

const createPool = require('@databases/pg');
const {sql} = require('@databases/pg');

// If you're using TypeScript or Babel, you can swap
// the two `require` calls for this import statement:

// import createPool, {sql} from '@databases/pg';

// create a "pool" of connections, you can think of this as a single
// connection, the pool is just used behind the scenes to improve
// performance
const db = createPool('postgres://localhost');

// wrap code in an `async` function so we can use `await`
async function run() {

  // we can run sql by tagging it as "sql" and then passing it to db.query
  await db.query(sql`
    CREATE TABLE IF NOT EXISTS beatles (
      name TEXT NOT NULL,
      height INT NOT NULL,
      birthday DATE NOT NULL
    );
  `);

  const beatle = {
    name: 'George',
    height: 70,
    birthday: new Date(1946, 02, 14),
  };

  // If we need to pass values, we can use ${...} and they will
  // be safely & securely escaped for us
  await db.query(sql`
    INSERT INTO beatles (name, height, birthday)
    VALUES (${beatle.name}, ${beatle.height}, ${beatle.birthday});
  `);

  console.log(
    await db.query(sql`SELECT * FROM beatles;`)
  );
}

run().catch(ex => {
  // It's a good idea to always report errors using
  // `console.error` and set the process.exitCode if
  // you're calling an async function at the top level
  console.error(ex);
  process.exitCode = 1;
}).then(() => {
  // For this little demonstration, we'll dispose of the
  // connection pool when we're done, so that the process
  // exists. If you're building a web server/backend API
  // you probably never need to call this.
  return db.dispose();
});

数据库：