I'm quite new to mongodb and I'm using sinatra and mongomapper to update the values of an embedded document with the following set up:
class TeamMember
include MongoMapper::Document
key :name, String, :required => true
many :team_member_projects
end
class TeamMemberProject
include MongoMapper::EmbeddedDocument
key :date, Date, :required => true
one :project
end
class Project
include MongoMapper::Document
key :name, String, :required => true
end
The modifier code is:
team_member = TeamMember.find(params[:team_member])
project = Project.find(params[:project])
date = Date.parse(params[:date])
tm_project = TeamMemberProject.new(:project => project, :date => date)
team_member.push(:team_member_projects => tm_project)
team_member.save
but I get the error for .push line:
BSON::InvalidDocument at /project/add
Cannot serialize an object of class TeamMemberProject into BSON.
Did I not declare my embedded document properly? Or is there another way to update embedded documents, I don't know about. I'm trying to use: http://mongomapper.com/documentation/plugins/modifiers.html#push
This seems to work
team_member = TeamMember.find(params[:team_member])
project = Project.find(params[:project])
date = Date.parse(params[:date])
tm_project = TeamMemberProject.new(:project_id => project.id, :date => date)
team_member.team_member_projects << tm_project
team_member.save
It seems like I have to use project.id. Not sure why. Also not sure why my .push doesn't work, as I would have assumed it does the same thing as <<.
Related
I'm creating a Sinatra App using Datamapper.
With the following route, I'm attempting to print the record for an id. So localhost:9292/api/1 should return results for id=1
inside
get '/api/:id' do
I tried a couple things with varied results:
thing = Thing.get(params[:id])
thing.to_json
end
outputs 'null', but:
id_param = params[:id]
id_param
end
prints 1 as expected, and:
hardcoded_thing = Thing.get(1)
hardcoded_thing.to_json
end
correctly prints the hardcoded db record with id=1. So I must be losing it..
Any ideas?
Thanks!
For reference, here's my model:
class Thing
include DataMapper::Resource
include BCrypt
property :id, Serial, :key => true
property :created_at, DateTime
property :updated_at, DateTime
property :name, String, :length => 50
property :cafe_topic, Text
end
Try this:
get '/api/:id' do |id|
thing = Thing.get(id)
thing.to_json
end
This is a get started example of Ruby data mapper. However, how does this example illustrate the power of datamapper that separate the application logic and data persistence?
Any better example can give us that the separation can lead us do unit test more easily?
class Post
include DataMapper::Resource
property :id, Serial # An auto-increment integer key
property :title, String # A varchar type string, for short strings
property :body, Text # A text block, for longer string data.
property :created_at, DateTime # A DateTime, for any date you might like.
end
# create makes the resource immediately
#post = Post.create(
:title => "My first DataMapper post",
:body => "A lot of text ...",
:created_at => Time.now
)
# Or new gives you it back unsaved, for more operations
#post = Post.new(:title => ..., ...)
#post.save # persist the resource
Thanks!
Here is my question.
I have 2 associated Datamapper models:
class Task
include DataMapper::Resource
property :id, Serial
property :date, Date
property :amount, Float
belongs_to :project, :required => true
end
class Project
include DataMapper::Resource
property :id, Serial
property :name, String, :required => true
property :desc, Text
belongs_to :company
has n, :tasks
end
My goal is to created JSON that will contain task date, amount and project name, that should be matched by project_id. At the moment JSON generation has following look:
Task.all.to_json(:only => [:date, :amount, :project_id])
I can access project_id from Task model, but have no idea how to add respective project name from Project model for every task. In SQL it looks like join:
select tasks.date, tasks.amount, projects.name from tasks
inner join projects
on tasks.project_id = projects.id;
Can you suggest correct way to create final JSON, using Datamapper way, but not SQL?
Thank you.
I have found solution for my problem. Here it is:
# create new structure to store merged result
Task_entry = Struct.new(:date, :amount, :pname)
# array to get results from database
all_task_items = Array.new
# run through result and fill the array with required data
Task.all.each do |task|
task_item = Task_entry.new(task.date, task.amount, task.project.name)
all_task_items << task_item
end
all_task_items.to_json # generate json
It works for me well. Hope it can be helpful.
I use mongo mapper (0.8.6) in my sinatra service. I have one problem with stack level too deep. The problem is that there is conflict of the key "changes" in my model. Here is my model:
class ChangeLog
include MongoMapper::Document
belongs_to :resource
key :changes, Hash, :required => true
key :message, String, :required => true
key :note, String
key :user_uuid, String, :required => true
key :user_name, String, :required => true
timestamps!
end
However, I don't want to rename my key as in this case, it's the right name for my web service. Any suggestions?
changes is an instance method that will tell you what fields have changed since you last saved the document. Here's an example from MongoMapper's documentation
user = User.create(:name => 'John', :age => 29)
puts user.changed? # false
puts user.changes.inspect # {}
user.name = 'Steve'
puts user.changed? # true
puts user.changes.inspect # {"name"=>["John", "Steve"]}
Unfortunately, you're probably going to need to choose a different name for that field. Maybe "adjustments" or "variations" or "differences" or "modifications"?
When I define the User has_many meetings, it automatically creates a "user_id"
key/value pair to relate to the User collections. Except I can't run any
mongo_mapper finds using this value, without it returning nil or [].
Meeting.first(:user_id => "1234")
Meeting.all(:user_id => "1234")
Meeting.find(:user_id => "1234")
All return nil. Is there another syntax? Basically I can't run a query on the automatically generated associative ObjectId.
# Methods
class User
include MongoMapper::Document
key :user_name, String, :required => true
key :password, String
many :meetings
end
class Meeting
include MongoMapper::Document
key :name, String, :required => true
key :count, Integer, :default => 1
end
# Sinatra
get '/add' do
user = User.new
user.meetings "foobar") #should read: Meeting.new(:name => "foobar")
user.save
end
get '/find' do
test = Meeting.first(:user_id => "4b4f9d6d348f82370b000001") #this is the _id of the newly create user
p test # WTF! returns []
end
As Jimmy mentioned about checking Meeting.all, I don't think you would have anything.
Based on your example above I see a couple potential issues.
- Your User requires a :user_name so it's not getting saved
- would never get saved, because you didn't set the name which is required
- Your Meeting isn't getting saved either
- One more thing, you need to concat your meeting to user.meetings
This works with mongo_mapper 0.6.10
require 'rubygems'
require 'mongo_mapper'
MongoMapper.database = "meetings"
class User
include MongoMapper::Document
key :user_name, String, :required => true
key :password, String
many :meetings
end
class Meeting
include MongoMapper::Document
key :name, String, :required => true
key :count, Integer, :default => 1
end
user = User.create(:user_name => "Rubyist")
user.meetings << Meeting.create(:name => "foobar")
user.save
Meeting.first(:user_id => user.id)
User.find(user.id).meetings
You may have figured this out already, but I hope this is helpful anyway.
You can try using
Meeting.find_by_user_id "1234"
Also, if you run script/console then does Meeting.all show each record as having a user_id assigned to it?
What about just User.find("1234").meetings ?