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PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

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HTTP status code symbols for Rails

Thanks to Cody Fauser for this list of HTTP responce codes and their Ruby on Rails symbol mappings.

Status Code Symbol
1xx Informational
100 :continue
101 :switching_protocols
102 :processing

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Intermediate SQL Workshop

• Run psql
• You may need to run CREATE DATABASE intermediate_sql;
• To exit this shell, you can run CTRL d

Create tables

Let's create some tables in the database.

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Rails Step By Step “Guide”

Start a new rails project:

Reference: https://github.com/turingschool-examples/task_manager_rails

This will start a new Rails App with postgresql as database and skip the usage of Spring and Turboline (method used in task_manager):

rails new task_manager -T -d="postgresql" --skip-spring --skip-turbolinks

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Ruby on Rails Cheatsheet

Architecture

Create a new application

Install the Rails gem if you haven't done so before

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Project Feedback

Name: Garrett

Partner: Sienna

Project Reflection

• What is one thing that went unusually well during this project?

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Render and Redirect

The normal controller/view flow is to display a view template corresponding to the current controller action, but sometimes we want to change that. We use render in a controller when we want to respond within the current request, and redirect_to when we want to spawn a new request.

Render

The render method is very overloaded in Rails. Most developers encounter it within the view template, using render :partial => 'form' or render @post.comments, but here we'll focus on usage within the controller.

:action

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Rails Models

Generating models

$ rails g model User

Associations

belongs_to

has_one

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ActiveRecord cheat sheet / EXAMPLES

INSTALL

$ gem install activerecord in GEMFILE: gem ‘activerecord’

REQUIRE

require ‘active_record’

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Rails Migration

http://guides.rubyonrails.org/migrations.html

Migrations methods:

• add_column
• add_index
• change_column
• change_table
• create_table
• drop_table