Simple ORM livecoding example

venue.rb

require 'pg'

$conn = PG::Connection.open(:dbname => 'lighthouse')

class Venue
    attr_accessor :name, :capacity, :id
    
    def initialize(name, capacity)
        @id = nil
        @name = name
        @capacity = capacity
    end

    def save
        if @id == nil
            sql = "INSERT INTO stagedocs_venue (name, capacity, city_id, notes, url, phone) VALUES ($1, $2, 1, '', '', '') RETURNING *"
            results = $conn.exec_params(sql, [@name, @capacity])
            @id = results[0]["id"]
        else
            sql = "UPDATE stagedocs_venue SET name=$1, capacity=$2 WHERE id=$3"
            $conn.exec_params(sql, [@name, @capacity, @id])
        end
            
    end

    def self.get_by_id(id)
        sql = "SELECT * FROM stagedocs_venue WHERE id=$1"
        results = $conn.exec_params(sql, [id])
        row = results[0]
        puts row.inspect
        venue = Venue.new(row["name"], row["capacity"])
        venue.id = row["id"]
        venue
    end
end

class Artist
    attr_accessor :name, :id
    
    def initialize(name)
        @id = nil
        @name = name
    end

    def save
        if @id == nil
            sql = "INSERT INTO stagedocs_artist () VALUES () RETURNING *"
            results = $conn.exec_params(sql, [@name, @capacity])
            @id = results[0]["id"]
        else
            sql = "UPDATE stagedocs_venue SET name=$1, capacity=$2 WHERE id=$3"
            $conn.exec_params(sql, [@name, @capacity, @id])
        end
            
    end

    def self.get_by_id(id)
        sql = "SELECT * FROM stagedocs_venue WHERE id=$1"
        results = $conn.exec_params(sql, [id])
        row = results[0]
        puts row.inspect
        venue = Venue.new(row["name"], row["capacity"])
        venue.id = row["id"]
        venue
    end
end


venue = Venue.new("New venue", 10000)
venue.save

venue.name = "Murat's Shack"
venue.save