Is there a way to do dbrefs using the Perl API? Its not here nor is it anywhere here.
Here s a sample schema:
book: name, publisher,isdn,{author}
author : name,date of birth
I could just add a field to serve as the reference but wanted to do it with dbref instead.
There are no helpers for it, yet. DBRefs are just normal hashes, though, so you can access/create them yourself. They have the form:
my $ref = {'$ref' => $collection_name, '$id' => $id};
See http://www.mongodb.org/display/DOCS/DB+Ref for more info.
It's also handled by MongoDBx::Class, but this is a fully fledged ORM so it may not fit your use case.
https://metacpan.org/pod/MongoDBx::Class
Its handle by MongoDBx::AutoDeref.
https://metacpan.org/pod/MongoDBx::AutoDeref
Related
I just have a short question.
There's no description in the following API overview of TYPO3 how to use a "BINARY" in where() clause: https://docs.typo3.org/m/typo3/reference-coreapi/master/en-us/ApiOverview/Database/QueryBuilder/Index.html#expr
What I want to achieve? this one:
WEHRE BINARY `buyer_code` = "f#F67d";
Actually I can only do the following:
->where(
$queryBuilder->expr()->eq('buyer_code', 'f#F67d')
);
But in this case I don't get a satisfying result for myself because I need case-sensitive here :-)
An another buyer_code exists "f#F67D" (the last char is uppercase) but I do need to look for the other one.
Thanks for helping.
Since TYPO3 is using Doctrine API here, you could try to do
->where('BINARY `buyer_code` = ' . $queryBuilder->createNamedParameter('f#F67d'))
Please keep in mind, that this query now only works for database backends, supporting the BINARY keyword!
Please have a look at Doctrine2 case-sensitive query The thread is a bit older, but seems to cover background and solution for your problem.
I want to be able to search for my objects by searching for the last 4 characters of the id. How can I do that?
Book.where(_id: params[:q])
Where the param would be something like a3f4, and in this case the actual id for the object that I want to be found would be:
bc313c1f5053b66121a8a3f4
Notice the last for characters are what we searched for. How can I search for just "part" of my objects id? instead of having my user search manually by typing in the entire id?
I found in MongoDB's help docs, that I can provide a regex:
db.x.find({someId : {$regex : "123\\[456\\]"}}) // use "\\" to escape
Is there a way for me to search using the regular mongo ruby driver and not using Mongoid?
Usually, in Mongoid you can search with a regexp like you normally would with a string in your call to where() ie:
Book.where(:title => /^Alice/) # returns all books with titles starting with 'Alice'
However this doesn't work in your case, because the _id field is not stored as a string, but as an ObjectID. However, you could add (and index) a field on your models which could provide this functionality for you, which you can populate in an after_create callback.
<shameless_plug>
Alternatively, if you're just looking for a shorter solution to the default Mongoid IDs, I could suggest something like mongoid_token which makes it pretty easy to add shorter tokens/ids to your Mongoid documents.
</shameless_plug>
how to use filter data as sql do "LIKE" in MongoDB, instead I using gem mongomapper on my rails apps? .thanks
If you're looking for partial matches on a string you can query with a regular expression. Here's the relevant part of the mongomapper docs:
http://api.mongodb.org/ruby/current/file.TUTORIAL.html#Querying_with_Regular_Expressions
Worth noting this from the Mongodb docs:
"For simple prefix queries (also called rooted regexps) like /^prefix/, the database will use an index when available and appropriate (much like most SQL databases that use indexes for a LIKE 'prefix%' expression). This only works if you don't have i (case-insensitivity) in the flags."
the closest thing to SQL LIKE would be /query/
ex:-
Person.where('name' => /John/).all => John F, John Doe, Johnny...etc
Edit: this is still case sensitive
try these it work for me :
#store_array=User.where(:$or => [{:first_name => /.#{#search_text}./i}, {:last_name => /.#{#search_text}./i}]).all();
here's my model:
class Person
acts_as_tree
end
i relate multiple objects as a tree:
P1
|
---
| |
P1.1 P1.2
|
---
| |
P1.1.1 P1.1.2
here if i need to retreive P1.1.1 i need to write a query that effectively asks:
get me the Person with name P1.1.1 and path (given by acts_as_tree) [P1, P1.1].
querying by just name is not enough as i can have similar named people at multiple paths.
how do i do this?
> db.people.find({name: 'P1.1.1'})
above snippet will show me the path attribute correctly as expected, but i cannot query by that path.
> db.people.find({name: 'P1.1.1', path: [{name: 'P1'}, {name: 'P1.1'}]})
doesn't work. neither does:
> db.people.find({name: 'P1.1.1', path: [db.people.find({name: 'P1'}),
db.people.find({name: 'P1.1'})]})
but that explains what i'm trying to do.
One of the ways where you can query something like as follows:
db.people.find({name : 'Joe', 'path' : { $all : [ObjectId("4e0fcf1722b7a9439200002e"), ObjectId("4e0fcf1622b7a9439200002b")]}})
However the drawback I think of this is:
You don't get to substitute the object relations/joins directly in mongo shell. You have to use the ObjectId object
The $all clause does not necessitate that the order of path is strictly same, which means that a person with name "Joe" referenced by path "hometown/town/" would come up as well as "Joe" from "tome/hometown".
I would presume that second one may be a deal breaker. Also, I am presuming that mongoid in several cases pass across the query options directly to mongodb (or atleast there are ways to do that). Hence it should be possible to do a search in ruby code using given query above.
Nevertheless, I'll do some more re-search on this and post my findings back.
Hope it helps.
Edit
To alleviate the second problem above there is also another way to query a person with a specific path. Find it below:
db.people.find({name : 'Joe', 'path.0' :ObjectId("4e0fcf1722b7a9439200002e"), 'path.1':ObjectId("4e0fcf1622b7a9439200002b")})
This would ensure that path is exactly what you are looking for. However this works in mongodb shell and you may still need to figure out, how mongoid can run an equivalent of this. Plus you may have to construct this query dynamically to create a path for person and that (for deep nested people) may just become long and ugly.
I would suggest skimming through following links on mongodb documentation to get a better understanding.
http://www.mongodb.org/display/DOCS/Dot+Notation+%28Reaching+into+Objects%29
http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-ValueinanArray
I hope this is what you were looking for.
This might sound like a trivial question, but it is rather important for consumer facing apps
What is the easiest way and most scalable way to map the scary mongo id onto a id that is friendly?
xx.com/posts/4d371056183b5e09b20001f9
TO
xx.com/posts/a
M
You can create a composite key in mongoid to replace the default id using the key macro:
class Person
include Mongoid::Document
field :first_name
field :last_name
key :first_name, :last_name
end
person = Person.new(:first_name => "Syd", :last_name => "Vicious")
person.id # returns "syd-vicious"
If you don't like this way to do it, check this gem: https://github.com/hakanensari/mongoid-slug
Define a friendly unique field (like a slug) on your collection, index it, on your model, define to_param to return it:
def to_param
slug
end
Then in your finders, find by slug rather than ID:
#post = Post.where(:slug => params[:id].to_s).first
This will let you treat slugs as your effective PK for the purposes of resource interaction, and they're a lot prettier.
Unfortunately, the key macro has been removed from mongo. For custom ids,
users must now override the _id field.
class Band
include Mongoid::Document
field :_id, type: String, default: ->{ name }
end
Here's a great gem that I've been using to successfully answer this problem: Mongoid-Slug
https://github.com/digitalplaywright/mongoid-slug.
It provides a nice interface for adding this feature across multiple models. If you'd rather roll your own, at least check out their implementation for some ideas. If you're going this route, look into the Stringex gem, https://github.com/rsl/stringex, and acts_as_url library within. That will help you get the nice dash-between-url slugs.