npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

reshuffle-pgsql-connector

v0.0.2

Published

Reshuffle connectors to PostgreSQL

Downloads

6

Readme

reshuffle-pgsql-connector

Code | npm | Code sample

npm install reshuffle-pgsql-connector

Reshuffle Postgres SQL Connector

This package contains a Reshuffle connector to Postgres SQL databases.

The following example lists all information from the "users" table:

const { Reshuffle } = require('reshuffle')
const { PgsqlConnector } = require('reshuffle-pgsql-connector')

;(async () => {
  const app = new Reshuffle()
  const pg = new PgsqlConnector(app, { url: process.env.POSTGRES_URL })

  const res = await pg.query(`SELECT * FROM users`)
  console.log(res)

  await pg.close()
})().catch(console.error)

Table of Contents

Configuration Configuration options

Connector actions:

close Close all active connections

query Run a single query on the database

sequence Run a series of queries on the databse

transaction Run a transaction on the databae

Configuration options
const app = new Reshuffle();
const pg = new PgsqlConnector(app, {
  url: "postgres://user[:password]@hostname[:port]/database",
  //Only include ssl option when connecting to a database protected by ssl
  ssl: {
    rejectUnauthorized: false,
    // Configure any of the relevant options below to your own ssl details
    ca: fs.readFileSync("/path/to/server-certificates/root.crt").toString(),
    key: fs.readFileSync("/path/to/client-key/postgresql.key").toString(),
    cert: fs
      .readFileSync("/path/to/client-certificates/postgresql.crt")
      .toString(),
  },
});

If connecting to a local database, ssl option is not needed and can be left blank.

For more information check the ssl and TLSSocket documentation.

Connector actions

Close action

Definition:

() => void

Usage:

await pg.close()

Close all connections to the database. If an application terminates without calling close, it might hang for a few seconds until active connections time out.

Query action

Definition:

(
  sql: string,
  params?: any[],
) => {
  fields: { name: string }[],
  rows: any[],
  rowCount: number,
}

Usage:

await pg.query("INSERT INTO users VALUES ('John', 'Coltrane', 42)")

const family = await pg.query(
  "SELECT firstName, lastName, age FROM users WHERE lastName='Coltrane'"
)
// {
//   rowCount: 2,
//   fields: [{ name: 'firstName' }, { name: 'lastName' }, { name: 'age' }],
//   rows: [
//     { firstName: 'Alice', lastName: 'Coltrane', age: 31 },
//     { firstName: 'John', lastName: 'Coltrane', age: 42 },
//   ],
// }

const avgResponse = await pg.query(
  "SELECT average(age) AS avg FROM users WHERE lastName='Coltrane'"
)
const averageAge = avgResponse.rows[0].avg
// 36.5

The query action can be used to run any SQL command on the connected database (not just SELECT). The query is defined in the sql string. The optional params can be used to generate parameterized queries, as shown in the following example:

const age = await pg.query(
  "SELECT age FROM users WHERE firstName=$1 and lastName=$2",
  ['John', 'Smith']
)

This action returns an object with the results of the query, where fields is an array of all field names, as returned by the query. Field names in a SELECT query are column names, or are specified with an AS clause. Every element of rows is uses the names in fields as its object keys.

Note that every call to query may use a different database connection. You can use the sequence or transaction actions if such a guarantee is required.

Sequence action

Definition:

(
  seq: (query) => any,
) => any

Usage:

const res = await pg.sequence(async (query) => {
  await query("INSERT INTO users VALUES ('Miles', 'Davis', 43)")
  return query("SELECT COUNT(*) FROM users")
})
const userCount = res.rows[0].count
// 3

Use sequence to perform multiple queries on the same database connection. This action receives a seq function that may issue queries to the database, all of which are guaranteed to run through the same connection. seq gets one argument, which is a query function that can be used the same way as the query action. seq may, of course, use any JavaScript code to implement its logic, log to the console etc.

Note that while sequence uses the same connection to run all queries, it does not offer the transactional guarantees offered by transaction. You can use it for weak isolation models, or construct transactions directly without using transaction.

Transaction action

Definition:

(
  seq: (query) => any,
) => any

Usage:

await pg.transaction(async (query) => {
  const res = await query("SELECT COUNT(*) FROM users")
  const userCount = res.rows[0].count
  if (100 <= userCount) {
    throw new Error('Too many users:', userCount)
  }
  return query("INSERT INTO users VALUES ('Charlie', 'Parker', 49)")
})

Use transaction to run multiple queries as an atomic SQL transaction. The interface is identical to the sequence action, but all the queries issued seq either success or fail together. If any of the queries fail, all queries are rolled back and an error is thrown.

Consider, for example, the following code for updating a bank account balance:

const accountId = 289
const change = +1000
pg.transaction(async (query) => {
  await query(`
    UPDATE accounts
      SET balance = balance + $1
      WHERE account_id = $2
    `,
    [change, accountId],
  )
  await query(`
    INSERT INTO accounts_log(account_id, change, time)
      VALUES ($1, $2, current_timestamp)
    `,
    [change, accountId],
  )
})

In the example above, accounts holds current balances of accounts, while accounts_log holds a history of all changes made. Using transaction ensures that both tables are always updated together.