ts-postgres

ts-postgres

Non-blocking PostgreSQL client for Node.js written in TypeScript.

Install

This library does not yet have a stable release. The following command installs the latest pre-release.

$ npm install ts-postgres@next

Features

• Fast!
• Binary protocol
• Multiple queries can be sent at once (pipeline)
• Extensible value model
• Hybrid query result object
  • Iteration (synchronous or asynchronous, yields one map per row);
  • All-at-once, when promise completes; result data is available in array form

Usage

The client uses an async/await-based programming model.

import { Client } from 'ts-postgres';

async function main() {
    const client = new Client();
    await client.connect();

    // The query result is an asynchronous iterator.
    const iterator = client.query(
        `SELECT 'Hello ' || $1 || '!' AS message`,
        ['world']
    );

    for await (const item of iterator) {
        console.log(item.get('message')); // 'Hello world!'
    }

    await client.end();
}

main()

We often want to just wait for the entire result set to arrive and subsequently process the data:

const result = await client.query('select generate_series(1, 10)');

The iterator interface yields one map object per row (from column names to values). The spread operator is a convenient way to turn a result into an array of such maps:

const items = [...result];
for (let item of items) {
  console.log('The number is: ' + item.get('i')); // 1, 2, 3, ...
}

Using the rows attribute is the most efficient way to work with result data. It contains the raw result data as an array of arrays.

for (let row of result.rows) {
  console.log('The number is: ' + row[0]); // 1, 2, 3, ...
}

Column names are available as the names attribute of a result.

Multiple queries

The query command accepts a single query only. If you need to send multiple queries, just call the method multiple times. For example, to send an update command in a transaction:

client.query('begin');
client.query('update ...');
await client.query('commit');

The queries are sent back to back over the wire, but PostgreSQL still processes them one at a time, in the order they were sent (first in, first out).

Notes

Queries are sent using the prepared statement variant of the extended query protocol. In this variant, the type of each parameter is determined prior to parameter binding, ensuring that values are encoded in the correct format.

The copy commands are not supported.

Benchmarking

Use the following environment variable to run tests in "benchmark" mode.

$ NODE_ENV=benchmark npm run test

Support

ts-postgres is free software. If you encounter a bug with the library please open an issue on the GitHub repo.

License

Copyright (c) 2018 Malthe Borch ([e-mail])

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.