Bootcamp week 3: Databases

This week we started learning about databases. Using Ruby and PostgreSQL, we completed a range of modules and challenges starting with simple single-table designs, right through to more complex multi-table joins.

It felt like a step up in difficulty, and most of us found it challenging to get through all the content. But working through the many (many!) errors I encountered during the week really helped develop my testing and debugging skills, and by the end of the week I was feeling fairly confident about creating schemas, seeds and SQL queries.

There were also plenty of opportunities to practice skills I started learning over the previous couple of weeks, including analysing user stories, creating design documents, and making diagrams to visualise how all the components fit together.

Shop Manager project

The final project of the week was to create a basic retail stock and order management system using Ruby.

I started off by designing the tables, classes and methods. For the Postgres database, I created orders and items tables, and an items_orders join table.

I used the colorize gem to spruce up the terminal output. I also created a Format class to handle output. It's something I started thinking about in the previous week's challenge, and it seems sensible to separate out all the repetitive spacing and tweaks needed to try and make the terminal output more reabable.

class Format
  def string(text = "", color = :default, spacing = "")
    return if text == ""
    text = text.colorize(color)
    text = "\n#{text}" if spacing == :pad || spacing == :before
    text = "#{text}\n" if spacing == :pad || spacing == :after
    return text
  end
  
  def currency(price)
    return sprintf("£%.2f", price)
  end
  
  def header(text)
    return string("====== #{text} ======", :red, :before)
  end
end

This lets me do something like Format.string("Lorem ipsum", :cyan, :pad), which will return “Lorem ipsum” in blue with linebreaks before and after.

Overall I was pretty pleased with the finished product. I put a lot of effort into the RSpec tests, and was happy to get 95% test coverage. Given more time, the next steps would be to implement error handling and better input validation.