I want to read entrys from a Database using active_record and keep getting diffrent Errors like: Name error and can't find the database or it can't execute the query.
so my question here is how do i read from a database or execute SQL-queries and for example write the result into a variable?
require 'rubygems'
require 'sinatra'
require 'active_record'
require 'sqlite3'
ActiveRecord::Base.establish_connection(
:adapter => "sqlite3",
:database => "test.db"
)
class Article < ActiveRecord::Base
end
#ActiveRecord::Migration.create_table :users do |t|
# t.string :name
#end
class App < Sinatra::Application
end
get '/' do
output = users.select(:all)
f = File.open('name','a'); f.write(output); f.close
#puts User.first
To read the data from the users table, you'd simply do:
class User < ActiveRecord::Base
end
get '/' do
#users = User.all
puts "Grabbed #{#users.size} user(s) from database"
end
Related
I am trying to create active record using Sinatra and Sinatra/active record, my migrations are getting migrated to the Postgres database but tables are not getting created in the database, I went through all the possible solutions on stack overflow but its of no use. I tried even deleting my migration files from db/migrate folder but still the same output. What must be the error
Gemfile
source 'https://rubygems.org'
gem "sinatra"
gem "pg" #for postgres
gem "activerecord"
gem "sinatra-activerecord"
config.ru
require "./app"
run Sinatra::Application
rakefile.rb
require "./app"
require "sinatra/activerecord/rake"
app.rb
require 'sinatra'
require 'sinatra/activerecord'
db = URI.parse('postgres://project1:project1#localhost/*****')
ActiveRecord::Base.establish_connection(
:adapter => db.scheme == 'postgres' ? 'postgresql' : db.scheme,
:host => db.host,
:username => db.user,
:password => db.password,
:database => db.path[1..-1],
:encoding => 'utf8'
)
class Note < ActiveRecord::Base
end
class CreateNotes < ActiveRecord::Migration
def up
create_table :notes do |t|
t.string :title
t.text :body
t.timestamps
end
end
def down
drop_table :notes
end
end
output of migration
user#user-Inspiron-5520:~/rails-apps/project1$ rake db:migrate
== 20150704053019 CreateNotes: migrating ======================================
== 20150704053019 CreateNotes: migrated (0.0000s) =============================
db output (psql)
\dt
List of relations
Schema | Name | Type | Owner
--------+-------------------+-------+-----------
public | schema_migrations | table | project1
(1 row)
project1=# select * from schema_migrations;
version
----------------
20150704053019
(1 row)
note: Project1 user is a super user with all privileges
EDIT
Migrations file 20150704053019_create_notes.rb
class CreateNotes < ActiveRecord::Migration
def change
end
end
I would first like to note that #limekin was the first to get the answer, commenting:
The migration you are using to create notes table is actually kept in app.rb. But the migrate task looks for migrations inside db/migrate. If the migration file you gave at the bottom is inside the right directory, then move the migration definition from app.rb to there.
I will just go into a bit more detail. The function that you are using to create the table belongs in the migration file, because a migration is what creates, changes and deletes tables, columns, and records.
So to solve your issue just move the function up in your app file into the change function in your migration file.
Here's the error I'm getting when I try to run my tests with RSpec:
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/infl
ector/methods.rb:230:in `block in constantize': uninitialized constant User (Nam
eError)
I'm trying to run FactoryGirl with RSpec but without Rails. Here are the files that take part in the testing:
user_spec.rb
require 'spec_helper'
module Bluereader
describe User do
describe 'login' do
user = FactoryGirl.build(:user)
end
describe 'logout' do
end
describe 'create_account' do
end
describe 'delete_account' do
end
end
end
spec/spec_helper
$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..'))
$LOAD_PATH.unshift(File.dirname(__FILE__))
require 'rspec'
require 'lib/bluereader'
require 'factory_girl'
FactoryGirl.find_definitions
spec/factories.rb
require 'digest/sha1'
FactoryGirl.define do
sequence(:username) { |n| "user-#{n}" }
factory :user do
username
encrypted_password Digest::SHA1.hexdigest('password')
full_name 'John Doe'
logged_in_at Time.now
logged_out_at 0
end
end
At this point I know that the factories.rb file is being loaded (I tried with the moronic print-debugging). When I remove the user = FactoryGirl.build(:user) line from user_spec.rb I get no errors (and the normal RSpec feedback telling me there are no tests, but no errors). If you are interested, here's my model:
require 'digest/sha1'
module Bluereader
class User < ActiveRecord::Base
has_many :categories, :foreign_key => :user_id
has_many :news, :foreign_key => :user_id
has_many :settings, :foreign_key => :user_id
attr_reader :full_name
class << self
def login(username, password)
encrypted_password = Digest::SHA1.hexdigest(password)
if not User.exists?(:username => username, :encrypted_password => encrypted_password)
user_id = User.id_from_username(username)
update(user_id, :logged_in_at => Time.now, :logged_out_at => 0)
end
end
def logout
update(current_user.id, :logged_out_at => Time.now)
end
def validate_account(username, password, full_name)
if username.empty? or password.empty or full_name.empty?
return 'Please fill in all the fields.'
end
if User.exists?(:username => username)
return 'That username is already in use.'
end
unless username =~ /^\w+$/
return 'Username field should contain only letters, numbers and underscores.'
end
''
end
def create_account(username, password, full_name)
encrypted_password = Digest::SHA1.hexdigest(password)
User.create(:username => username,
:encrypted_password => encrypted_password,
:full_name => full_name,
:logged_in_at => Time.now,
:logged_out_at => 0)
end
def delete_account
current_user.destroy
end
private
def id_from_username(username)
user = where(:username => username).first
user.nil? ? 0 : user.id
end
def current_user
where(:logged_out_at => 0).first
end
end
end
end
SOLUTION
The problem was that the class User was in a module, here's the solution:
factory :user, class: Bluereader::User do
You need to require the rails environment in your spec helper file. Add the following to spec/spec_helper.rb:
require File.expand_path("../../config/environment", __FILE__)
Update
Even if you're not using Rails, you'll still need to require the models in your spec helper.
Taken from the bottom of the question
The problem was that the class User was in a module, here's the solution:
factory :user, class: Bluereader::User do
For anyone clumsy like me, you may have FactoryGirl in your code where you meant to have FactoryBot
I have the following code:
require 'rubygems'
require 'aws-sdk'
require 'sqlite3'
require 'active_record'
db = SQLite3::Database.new('awsec2.db')
ActiveRecord::Base.establish_connection(
:adapter=> "sqlite3",
:database=> "awsec2")
ActiveRecord::Schema.define do
create_table :instances do |t|
t.column :instance_id, :string
t.column :status, :string
end
end
ACCESS_KEY_ID = '.......................'
SECRET_ACCESS_KEY = '....................'
ec2 = AWS::EC2.new(:access_key_id => ACCESS_KEY_ID, :secret_access_key => SECRET_ACCESS_KEY)
ec2.instances.inject({}) { |m, i| m[i.id] = i.status; m } # How to pass those items to the instances table
How to store the data collected by ec2.instances methode to the database table?
Here is metadata query tool made by amazon. It is just a helper script to fetch data from metadata url.
I have a problem I can't figure out here. I'm writing a ruby script that deals with an sqllite database.
require 'rubygems'
require 'sqlite3'
require 'active_record'
ActiveRecord::Base.establish_connection(
:adapter => "sqlite3",
:database => "../database/my.db"
)
class KeyWord < ActiveRecord::Base
set_table_name "keywords"
end
# THIS STATEMENT WORKS (finds the first record, returns "ruby") :
KeyWord.find(1).keyval
# THOSE STATEMENTS RETURN NO RESULT :
KeyWord.find(:all, :conditions => {:keyval => "ruby"})
KeyWord.find_by_sql("SELECT * FROM keywords WHERE keyval='ruby'")
KeyWord.find_by_keyval("ruby")
This is how the table was created :
create_table :keywords do |table|
table.column :keyval, :text
end
Does anyone know where this could come from ?
Thanks,
R.
I see a couple of issues here.
I'm not sure why you're manually setting your table name.
ActiveRecord assumes that your model name is camelCased. So... AR
would, by default, search for a table called key_words. Why not just
go with that?
Pay attention to which version of active record you are
using. Passing in conditions is deprecated. You should be using the
.where syntax. So... you would need to do KeyWord.where(:keyval
=> 'ruby').first or end in .all for a collection of results.
If you are just fooling around, you can use sqlite3 in memory.
ActiveRecord::Base.establish_connection( adapter: 'sqlite3',
database: ":memory:")
Also don't forget to define your schema!
Here is full code w/ more modern syntax.
require 'rubygems'
require 'sqlite3'
require 'active_record'
ActiveRecord::Base.establish_connection( adapter: 'sqlite3', database: ":memory:" )
ActiveRecord::Migration.verbose = false
ActiveRecord::Schema.define(version: 2) do
create_table :key_words do |t|
t.text :keyval
end
end
class KeyWord < ActiveRecord::Base
end
Keyword.create!(:keyval => 'ruby')
# THESE STATEMENTS WORK:
KeyWord.find(1).keyval
KeyWord.where(:keyval => 'ruby').first
KeyWord.where(:keyval => 'ruby').all
KeyWord.find_by_sql("SELECT * FROM key_words WHERE keyval='ruby'")
KeyWord.find_by_keyval("ruby")
I'm using Sinatra, EventMachine, DataMapper, SQLite3 and the Twitter Stream API to capture and save tweets. When I run the application from my command line, it seems to continually fail at tweet 50. If I'm not saving the tweets, it can run seemingly forever.
Below is the app code to capture tweets with 'oscar' in them, which provided a very quick stream. Just enter your twitter username and password and run at the command line.
require 'rubygems'
require 'sinatra'
require 'em-http'
require 'json'
require 'dm-core'
require 'dm-migrations'
USERNAME = '<your twitter username>'
PASSWORD = '<your secret password>'
STREAMING_URL = 'http://stream.twitter.com/1/statuses/filter.json'
DataMapper.setup(:default, ENV['DATABASE_URL'] || "sqlite3://#{Dir.pwd}/db/development.db")
class Tweet
include DataMapper::Resource
property :id, Serial
property :tweet_id, String
property :username, String
property :avatar_url, String
property :text, Text
end
DataMapper.auto_upgrade!
get '/' do
#tweets = Tweet.all
erb :index
end
def rip_tweet(line)
#count += 1
tweet = Tweet.new :tweet_id => line['id'],
:username => line['user']['screen_name'],
:avatar_url => line['user']['profile_image_url'],
:text => line['text']
if tweet.save
puts #count
else
puts "F"
end
end
EM.schedule do
#count = 0
http = EM::HttpRequest.new(STREAMING_URL).get({
:head => {
'Authorization' => [ USERNAME, PASSWORD]
},
:query => {
'track' => 'oscars'
}
})
buffer = ""
http.stream do |chunk|
buffer += chunk
while line = buffer.slice!(/.+\r?\n/)
rip_tweet JSON.parse(line)
end
end
end
helpers do
alias_method :h, :escape_html
end
I'm not sure you can safely mix EM and Sinatra in the same process. You might want to try splitting the Sinatra viewer and the EventMachine downloader into separate programs and processes.