pg-promise-strict

postgresql with promises and strict types and returning size of results

Usage no npm install needed!

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README

pg-promise-strict

postgresql with promises and strict types and returning size of results

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language: English also available in: Spanish

Features

PG Promise/A+ in the strict way:

  • The same functions, with the same name and same retunrs that in PG, but without callbacks
  • covers 100% by test.
  • 100% coded in typescript
  • No reimplement nothing that PG does
  • Some additions for comfort

Install

$ npm install pg-promise-strict

Use example

var pg = require('pg-promise-strict');

var conOpts = {
    user: 'test_user',
    password: 'test_pass',
    database: 'test_db',
    host: 'localhost',
    port: 5432
};

pg.connect(conOpts).then(function(client){
    return client.query('select * from table').execute().then(function(result){
        for(var i=0; i<result.rowCount; i++){
            console.log('row',i,result.rows[i]);
        }
        client.done();
    });
}).catch(function(err){
    console.log('ERROR',err);
});

Examples of PG

The first easy example. One simple query that returns all rows. Example based in PG

var pg = require('pg-promise-strict');

var conString = "postgres://username:password@localhost/database";

try{
    var client = await pg.connect(conString)
    var result = await client.query('SELECT $1::int AS number', ['1']).fetchAll();
    console.log(result.rows[0].number);
}catch(err){
    console.error('error fetching client from pool or running query', err);
};

In this example you see:

  • async calls
  • parameters passed to libpq in the query function
  • the fetchAll function that convirms that you want all rows.

Example without connection pool

Corresponds to calls to PG direct client instance

var pg = require('pg-promise-strict');

var conString = "postgres://username:password@localhost/database";

var client = new pg.Client(conString);

try{
    await client.connect();
    var result = await client.query('SELECT NOW() AS "theTime"').fetchAll();
    console.log(result.rows[0].theTime);
    console.log(row.name);
    client.done();
}catch(err){
    console.error('error connecting or running query', err);
});

Example with fetch row by row

Corresponds to calls to PG.query without callback. In PG documentation Brian C says do not provide callback function for large result sets unless you're okay with loading the entire result set into memory

This is the way for process data row by row

var client = await pg.connect({user: 'brianc', database: 'test'});
await client.query("SELECT name FROM users").onRow(function(row){
    console.log(row.name);
});
client.done();
console.log('ready.');

In this example you see:

  • the on-row callback
  • the await until the query has finished

Running the examples

In the examples directory the create_db.sql script can be used to create de test database. In the same directory there are the example slightly modified.

Running tests

Clone the repository and install the developer dependencies in then normal way. You must provide a postgresql-9.3 instalation for create a test_db. Then you can test pg-promise-strict

$ git clone git://github.com/codenautas/pg-promise-strict.git pg-promise-strict
$ cd pg-promise-strict
$ npm install
$ psql --file test/create_db.sql
$ npm test

License

MIT