I am using Sinatra and DataMapper with MySQL and i getting issues when i query the database.
My models.rb is the folloging:
require 'sinatra'
require 'dm-core'
require 'dm-migrations/adapters/dm-mysql-adapter'
DataMapper::Logger.new("log/datamapper.log", :debug)
DataMapper.setup(:default, 'mysql://user:password#localhost/testdb')
class Item
include DataMapper::Resource
property :id, Serial
property :item, String, :length => 50
end
DataMapper.finalize
DataMapper.auto_upgrade!
Item.create(item:"item_one")
Item.create(item:"item_two")
The items are inserted in the database but when i query de database always returns nil values, example:
(rdb:1) #items =Item.all
[#<Item #id=nil #item=nil>, #<Item #id=nil #item=nil>]
if i query the numbers of items i get the expected result:
(rdb:1) #items.count
2
I have tried to make a query directly getting the same result :
adapter = DataMapper.repository(:default).adapt
adapter.select("SELECT * FROM items")
Does anyone know what I'm doing wrong or have suggestions on what to look for to fix problem?
Add these two lines to models.rb:
adapter = DataMapper.repository(:default).adapter
print adapter.select("SELECT * FROM items")
(Notice .adapter, not .adapt.) It prints
[#<struct id=1, item="item_one">, #<struct id=2, item="item_two">]
Everything works as expected (ruby 2.1.7p400 (2015-08-18 revision 51632)).
Related
Rails 5 now support native JSON data type in MySQL, so if I have a column data that contains an array: ["a", "b", "c"], and I want to search if this column contains values, so basically I would like to have something like: data_json_cont: ["b"]. So can this query be built using ransack ?
Well I found quite some way to do this with Arrays(not sure about json contains for hash in mysq). First include this code in your active record model:
self.columns.select{|column| column.type == :json}.each do |column|
ransacker "#{column.name}_json_contains".to_sym,
args: [:parent, :ransacker_args] do |parent, args|
query_parts = args.map do |val|
"JSON_CONTAINS(#{column.name}, '#{val.to_json}')"
end
query = query_parts.join(" * ")
Arel.sql(query)
end
end
Then assuming you have class Shirt with column size, then you can do the following:
search = Shirt.ransack(
c: [{
a: {
'0' => {
name: 'size_json_contains',
ransacker_args: ["L", "XL"]
}
},
p: 'eq',
v: [1]
}]
)
search.result
It works as follows: It checks that the array stored in the json column contains all elements of the asked array, by getting the result of each json contains alone, then multiplying them all, and comparing them to arel predicate eq with 1 :) You can do the same with OR, by using bitwise OR instead of multiplication.
I have 2 objects, Visitors and Events. Visitors have multiple Events. An event stores parameters like this...
#<Event id: 5466, event_type: "Visit", visitor_token: "c26a6098-64bb-4652-9aa0-e41c214f42cb", contact_id: 657, data: {"url"=>"http://widget.powerpress.co/", "title"=>"Home (light) | Widget"}, created_at: "2015-12-17 14:51:53", updated_at: "2015-12-17 14:51:53", website_id: 2>
As you can see, there is a serialized text column called data that stores a hash with more data.
I need to find out if a visitor has visited a certain page, which would be very simple if the url parameter were it's own column, or if the hash were an hstore column, however it wasn't originally set up that way and it's a part of the saved hash.
Here's my attempted rails queries...
visitor.events.where("data -> url = :value", value: 'http://widget.powerpress.co/')
visitor.events.where("data like ?", "{'url' => 'http://widget.powerpress.co/'}")
visitor.events.where("data -> :key LIKE :value", :key => 'url', :value => "%http://widget.powerpress.co/%")
How does one properly query postgres to find objects that have a hash that contains a key with a specific value?
I suspect you're not looking for the right string. It should be "url"=>"http://widget.powerpress.co/", so:
visitor.events.where("data like ?", '%"url"=>"http://widget.powerpress.co/"%')
Check the right value directly in DB.
If you are storing hash in a text column, try following:
visitor.events.select{|ve| eval(ve.data)["url"] == "http://widget.powerpress.co/"}
Hope, it helps!
It worked for me.
visitor.events.select { |n| n.data && n.data['url'] == "http://widget.powerpress.co/"}
I am saving a list of followed users to the db and then trying to get the records where the current user is a part of that list but keep getting this exception.
SQLite3::SQLException: no such column: parameters.user: SELECT "activities".* FROM "activities" WHERE "parameters"."user" = 3
This is a record in the db
=> #<PublicActivity::Activity id: 107, trackable_id: 16, trackable_type: "Shout", owner_id: 1, owner_type: "User", key: "shout.shout", parameters: {:user=>[3]}, recipient_id: nil, recipient_type: nil, created_at: "2015-10-20 21:44:41", updated_at: "2015-10-20 21:44:41", read: false>
These are the queries I've tried that give me this. current_user.id = 3
PublicActivity::Activity.where({'parameters.user' => current_user.id})
PublicActivity::Activity.where(parameters: {user: current_user.id})
So. How do I get the records where the current user is a part of that list of users? Also, would the I be able to use the same query in Mysql?
Might seem like a silly question, but is the parameters column defined as a serialized column in the model? With adapters like MySQL and (I believe) SQLite you can't query serialized fields. So If it's something that you'd like to query, you need to save it separately from the serialized field.
That being said, with PostgreSQL and their rails adapter, you can query serialized fields.
You should check out this SO question and this anser
I've stared at this so long I'm going in circles...
I'm using the rbvmomi gem, and in Pry, when I display an object, it recurses down thru the structure showing me the nested objects - but to_json seems to "dig down" into some objects, but just dump the reference for others> Here's an example:
[24] pry(main)> g
=> [GuestNicInfo(
connected: true,
deviceConfigId: 4000,
dynamicProperty: [],
ipAddress: ["10.102.155.146"],
ipConfig: NetIpConfigInfo(
dynamicProperty: [],
ipAddress: [NetIpConfigInfoIpAddress(
dynamicProperty: [],
ipAddress: "10.102.155.146",
prefixLength: 20,
state: "preferred"
)]
),
macAddress: "00:50:56:a0:56:9d",
network: "F5_Real_VM_IPs"
)]
[25] pry(main)> g.to_json
=> "[\"#<RbVmomi::VIM::GuestNicInfo:0x000000085ecc68>\"]"
Pry apparently just uses a souped-up pp, and while "pp g" gives me close to what I want, I'm kinda steering as hard as I can toward json so that I don't need a custom parser to load up and manipulate the results.
The question is - how can I get the json module to dig down like pp does? And if the answer is "you can't" - any other suggestions for achieving the goal? I'm not married to json - if I can get the data serialized and read it back later (without writing something to parse pp output... which may already exist and I should look for it), then it's all win.
My "real" goal here is to slurp up a bunch of info from our vsphere stuff via rbvmomi so that I can do some network/vm analysis on it, which is why I'd like to get it in a nice machine-parsed format. If I'm doing something stupid here and there's an easier way to go about this - lay it on me, I'm not proud. Thank you all for your time and attention.
Update: Based on Arnie's response, I added this monkeypatch to my script:
class RbVmomi::BasicTypes::DataObject
def to_json(*args)
h = self.props
m = h.merge({ JSON.create_id => self.class.name })
m.to_json(*args)
end
end
and now my to_json recurses down nicely. I'll see about submitting this (or the def, really) to the project.
The .to_json works in a recursive manner, the default behavior is defined as:
Converts this object to a string (calling to_s), converts it to a JSON string, and returns the result. This is a fallback, if no special method to_json was defined for some object.
json library has added some implementation for some common classes (check the left hand side of this documentation), such as Array, Range, DateTime.
For an array, to_json first convert all the elements to json object, concat then together, and then add the array mark [/].
For your case, you need to define your customized to_json method for GuestNicInfo, NetIpConfigInfo and NetIpConfigInfoIpAddress. I don't know your implementation about these three classes, so I wrote a example to demonstrate how to achieve this:
require 'json'
class MyClass
attr_accessor :a, :b
def initialize(a, b)
#a = a
#b = b
end
end
data = [MyClass.new(1, "foobar")]
puts data.to_json
#=> ["#<MyClass:0x007fb6626c7260>"]
class MyClass
def to_json(*args)
{
JSON.create_id => self.class.name,
:a => a,
:b => b
}.to_json(*args)
end
end
puts data.to_json
#=> [{"json_class":"MyClass","a":1,"b":"foobar"}]
I have to following table:
Relations
[id,user_id,status]
1,2,sent_reply
1,2,sent_mention
1,3,sent_mention
1,4,sent_reply
1,4,sent_mention
I am looking for a way to remove duplicates, so that only the following rows will remain:
1,2,sent_reply
1,3,sent_mention
1,4,sent_reply
(Preferably using Rails)
I know this is way late, but I found a good way to do it using Rails 3. There are probably better ways, though, and I don't know how this will perform with 100,000+ rows of data, but this should get you on the right track.
# Get a hash of all id/user_id pairs and how many records of each pair
counts = ModelName.group([:id, :user_id]).count
# => {[1, 2]=>2, [1, 3]=>1, [1, 4]=>2}
# Keep only those pairs that have more than one record
dupes = counts.select{|attrs, count| count > 1}
# => {[1, 2]=>2, [1, 4]=>2}
# Map objects by the attributes we have
object_groups = dupes.map do |attrs, count|
ModelName.where(:id => attrs[0], :user_id => attrs[1])
end
# Take each group and #destroy the records you want.
# Or call #delete instead to save time if you don't need ActiveRecord callbacks
# Here I'm just keeping the first one I find.
object_groups.each do |group|
group.each_with_index do |object, index|
object.destroy unless index == 0
end
end
It is better to do it through SQL. But if you prefer to use Rails:
(Relation.all - Relation.all.uniq_by{|r| [r.user_id, r.status]}).each{ |d| d.destroy }
or
ids = Relation.all.uniq_by{|r| [r.user_id, r.status]}.map(&:id)
Relation.where("id IS NOT IN (?)", ids).destroy_all # or delete_all, which is faster
But I don't like this solution :D