Todd Siegel toddsiegel

Installing rebenv

Mint comes with a ruby package installed. It is installed as the root user and is not the latest version. We want the flexibility to install the latest version, to be able to easily upgrade and not have the hassles of installing gems as root.

To do this we need to use Ruby environment manager. This allows everyone on your team to be on the same version of Ruby, regardless of OS. This can be locked in with a .ruby-version in the root directory of your project.

I recommend rbenv to do this.

Dependencies

The software we're installing needs a few dependencies installed in order to work.

Migrating a Rails project from MySQL to PostgreSQL

This brief guide is written from my own experience with migrating a large (~5GB) MySQL database to PostgreSQL for a Rails project.

No warranties, guarantees, support etc. Use at your own risk and, as always, ENSURE YOU MAKE BACKUPS FIRST!

I chose [pgloader][1] because it's extremely fast. YMMV.

Replace mysql2 gem with pg in Gemfile.
Update config/database.yml for PostgreSQL. I used [Rails' template][2] as a starting point.

Get object count

$ aws s3 ls s3://<bucketname> --recursive | wc -l

	SELECT t.table_name, ccsa.character_set_name
	FROM information_schema.tables t
	JOIN information_schema.collation_character_set_applicability ccsa
	ON ccsa.collation_name = t.table_collation
	WHERE t.table_schema = '<schema_name>'
	ORDER BY t.table_name

	gem 'pg'
	gem 'puma'
	gem 'rack-attack'
	gem 'rollbar'

	gem_group :development, :test do
	gem 'rubocop'
	end

	gem_group :test do

	# `read`
	## Basic usage
	$ read -p "Useful prompt goes here"

	## Use readline
	$ read -e -p "..."

	-- List all Foreign Keys
	select kcu.table_schema \|\| '.' \|\|kcu.table_name as foreign_table,
	'>-' as rel,
	rel_tco.table_schema \|\| '.' \|\| rel_tco.table_name as primary_table,
	string_agg(kcu.column_name, ', ') as fk_columns,
	kcu.constraint_name
	from information_schema.table_constraints tco
	join information_schema.key_column_usage kcu
	on tco.constraint_schema = kcu.constraint_schema
	and tco.constraint_name = kcu.constraint_name

	package com.solera.domain;

	import com.opencsv.bean.CsvBindByName;

	import java.util.Objects;

	public class LogEntry {
	@CsvBindByName(column = "insertId")
	private String insertId;

	const exportRows = [
	["Name", "Email"],
	["Foo Bar", "[email protected]"]
	];

	const csvContent = "data:text/csv;charset=utf-8," + exportRows.map((e) => e.join(",")).join("\n");
	const encodedUri = encodeURI(csvContent);
	const link = document.createElement("a");
	link.setAttribute("href", encodedUri);
	link.setAttribute("download", "export.csv"); // https://caniuse.com/#feat=download

	# frozen_string_literal: true

	module UsesTempfile
	def with_tempfile(name: 'temp-zip-file', temp_dir: Rails.root.join('tmp').to_s, binmode: false)
	tempfile = Tempfile.new('temp-zip-file', temp_dir)
	tempfile.binmode if binmode

	yield tempfile
	ensure
	tempfile.close