Murmuration for PostGreSQL

Statements, transactions and migrations for PostGreSQL.

This package is based largely on the following parent one:

• Murmuration

This readme file contains a small amount of information specific to this package, however the parent package's readme file is the place to look for how to make use of this package's functionality.

Installation

You can install Murmuration for PostGreSQL with npm:

npm install murmuration-postgresql

You can also clone the repository with Git...

git clone https://github.com/djalbat/murmuration-postgresql.git

...and then install the dependencies with npm from within the project's root directory:

npm install

Usage

General usage instructions are given in the aforementioned parent package's readme file.

const murmuration = require("murmuration-postgresql"); ///

const { database, migrate, transaction, Connection } = murmuration,
      { query, execute } = database;

...

This package leverages the pg package and uses its parameterised queries. This guard against SQL injection without further ado.

Configuration

The configuration argument should be a plain old JavaScript object with at least the following properties:

{
  host,
  user,
  password,
  database
}

In fact the user and password properties can be left off for trusted connections.

As mentioned in the parent package's readme file, if a log property is provided on the configuration object then the log.error() function will be called with a message containing a reasonable stab at the cause of the error. Specifically, the following error codes are mapped to the following messages:

• ECONNREFUSED - 'The database isn\'t running, probably.'

• ENOTFOUND - 'The host is wrong, probably.'

• 3D000 - 'The database name is wrong, probably.'

• 28000 - 'The username or the password are wrong, probably.'

In the remaining cases the error code is simply echoed and the offending SQL, if there is any, will also be echoed in a separate call to the log.error() function.

Placeholders

A variable length list of parameters can be passed between the sql and callback arguments of both the query() and execute() functions. These replace the $# placeholders in the SQL you provide. For example, if the SQL passed to the query() function is the following...

  SELECT * FROM user WHERE username=$1 and `password`=MD5($2);

...then you would call the query() function thus:

const username = ... ,
      password = ... ;

query(connection, sql, username, password, (error, rows) => {

  ...

});

The execute() function is treated entirely similarly.

For more information on placeholders and performing queries in general, see the pg package documentation here.

Contact

• [email protected]