#node-postgres-autopatch

Node application for automatically applying postgreSQL database patches.

#Features

• Automatic database patch application
• SQL patches
• Javascript patches

#Installation

npm install pg-autopatch

#Examples

var path = require('path');
var autopatch = require('pg-autopatch');

var config = {
	patchDir: path.resolve(__dirname, './patches/'),
	dbType: 'postgres',
	db: {
		host: 'localhost',
		port: 5432,
		user: 'postgres',
		database: 'db_name',
		password: 'password',
		patchTableName: 'patches'
	}
};

autopatch.run(config, function(err, newPatchesApplied) {
	console.log('autopatch done. %d new patches applied', newPatchesApplied);
});

#Notes

postgres-autopatch will create a table in the specified database called 'db_patch', in order to keep track of the applied patches. It will look in the patch directory specified in the config object for new patches to apply. New patches should be placed in this directory and postgres-autopatch will apply them when the autopatcher's run method is called. run should be called on application startup, so that it finishes before any server logic is executed. Patches should have names following the pattern db_001_patch_name.sql or db_002_patch_name.js.

##SQL Patches

An SQL patch file can be any valid SQL file. Every statement in the patch file will be executed in sequence.

##Javascript Patches

postgres-autopatch also supports javascript patch files, where more complex patches can be applied with logic. Javascript patch files must adhere to a specific format in order for them to be applied correctly. For Example:

var pg = require('pg');

module.exports = function(dbConfig, callback) {

	pg.connect(dbConfig, function(err, client, done) {
		var sql = "SELECT * FROM test_table";
		
		client.query(sql, function(err, response) {
			console.log(response);
			done();
		});
	});
};

You must use require('pg') in the patch file and export a function with a dbConfig and callback parameter. You may then use the dbConfig object to connect to the database and query using whatever logic you want.