lack of quickstart about rom-sql HOT 22 CLOSED

Thanks this got me a step closer to a working start, I now have this:

require 'rom'
require 'rom-repository'

rom = ROM.container(:sql, 'sqlite:test.db') do |config|

  class LibraryCollections < ROM::Relation[:sql]
    schema('AgLibraryCollection', infer: true)  
  end
  
  config.register_relation(LibraryCollections)
end

class LibraryCollectionRepo < ROM::Repository[:library_collections]  
end

repo = LibraryCollectionRepo.new(rom)
p repo.library_collections.to_a

But it fails on line 8 with:

sequel-4.42.1/lib/sequel/database/query.rb:162:in `schema': schema parsing returned no columns, table "AgLibraryCollection" probably doesn't exist (Sequel::Error)
	from rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:41:in `call'
	from rom-sql-0.9.1/lib/rom/sql/relation.rb:47:in `block (2 levels) in inherited'
	from rom-2.0.2/lib/rom/schema.rb:83:in `finalize!'
	from rom-sql-0.9.1/lib/rom/sql/schema.rb:24:in `finalize!'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:53:in `build_relation'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:25:in `block (2 levels) in run!'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:24:in `each'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:24:in `block in run!'
	from rom-2.0.2/lib/rom/relation_registry.rb:6:in `initialize'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:23:in `new'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:23:in `run!'
	from rom-2.0.2/lib/rom/setup/finalize.rb:93:in `load_relations'
	from rom-2.0.2/lib/rom/setup/finalize.rb:62:in `run!'
	from rom-2.0.2/lib/rom/create_container.rb:35:in `finalize'
	from rom-2.0.2/lib/rom/create_container.rb:13:in `initialize'
	from rom-2.0.2/lib/rom/create_container.rb:54:in `initialize'
	from rom-2.0.2/lib/rom/create_container.rb:59:in `new'
	from rom-2.0.2/lib/rom/create_container.rb:59:in `container'

I know the table does exists:

$ sqlite3 test.db "SELECT COUNT(*) FROM AgLibraryCollection"
4

I have been following rom for a while and I like the design, the current documentation is a great start but you are right, providing enough data without overloading the reader might prove difficult :)

I always prefer to have something working quickly even if I don't get all the principles behind it and then starting from that I can tweak things and see how it reacts and change my result, after that I can read more about how things work. I think maintaining a list of quickstarts instead of one is a good solution, you already have the read/write case, adding the read case might help others too.

from rom-sql.

Oh, I didn't notice your connection URI is not right, it should be a valid uri with path to your db file so something like sqlite:///path/to/your/test.db

from rom-sql.

Here's a quick start: http://rom-rb.org/learn/repositories/quick-start/

Here what I managed to write (and does not work):

What doesn't work exactly? Any backtrace?

from rom-sql.

The error I get from the code above is:

rom-2.0.2/lib/rom/relation.rb:90:in `each': undefined method `each' for #<ROM::Container:0x007ff7f2046e78> (NoMethodError)
	from rom-2.0.2/lib/rom/relation.rb:119:in `each'
	from rom-2.0.2/lib/rom/relation.rb:119:in `to_a'
	from rom-2.0.2/lib/rom/relation.rb:119:in `to_a'
	from app.rb:26:in `<main>'

I did not link it because I am pretty sure I am just doing something wrong.

I saw the quickstart and read the documentation but it is really fragemented, I don't yet understand how to piece things together to have a working base, from what I got I need to:

• create a container which is the database connection
• create one or more relations, create_table as used in the example does not work for I supposed since I don't want to alter the existing schema, just use it that's why I tried to create it myself
• create the repository, maybe ? I tried but also failed:

class LibraryCollection < ROM::Relation[:sql]
end

class LibraryCollectionRepo < ROM::Repository[???]
end

# for the question marks I tried :library_collection but it says it does not know the relation, also tried to put the class name itself "LibraryCollection" but did not work either
# => rom-support-2.0.0/lib/rom/support/registry.rb:33:in `block in fetch': :library_collection doesn't exist in ROM::RelationRegistry registry (ROM::Registry::ElementNotFoundError)

If you could provide a fully working starting point it would really help, and no the quickstart is not that for me, it shows one usecase but this is not mine and I can't manage to translate it which is really frustrating :(

from rom-sql.

If you just want to connect to an existing database and define an explicit relation class then you want this:

require 'rom'
require 'rom-repository'

rom = ROM.container(:sql, 'sqlite:test.db') do |config|
  # this assumes you have a table called :library_collections
  class LibraryCollections < ROM::Relation[:sql]
    schema(infer: true)
  end
  
  config.register_relation(LibraryCollections)
end

class LibraryCollectionRepo < ROM::Repository[:library_collections]
end

repo = LibraryCollectionRepo.new(rom)

p repo.library_collections.to_a

it shows one usecase but this is not mine and I can't manage to translate it which is really frustrating :(

We'll be working on new/more docs/guides. It's extremely difficult to document rom due to its broad functionality, and very little time, it's slowly progressing in a better direction. I'll add quick start section for connecting to an existing database too.

Thanks for feedback. Let me know if you need more help, I hope the example I showed will work for you.

from rom-sql.

If your table is called differently than the name you'd like to use, then you need to provide it as a symbol and you can alias it like that:

  class LibraryCollections < ROM::Relation[:sql]
    register_as :library_collections
    schema(:AgLibraryCollection, infer: true)
  end

if you switch to rom-sql 1.0.0.beta2 you can also do this:

  class LibraryCollections < ROM::Relation[:sql]
    schema(:AgLibraryCollection, infer: true, as: :library_collections)
  end

I always prefer to have something working quickly even if I don't get all the principles behind it and then starting from that I can tweak things and see how it reacts and change my result, after that I can read more about how things work.

Yep I'm the same, I'll definitely add short intros like that. It should probably go to a different section of the site, maybe "Guides" where this type of docs fit better. "Learn" section is meant to be a detailed documentation about all rom components with examples how to use various APIs.

from rom-sql.

I tried with a symbol and it still did not work (same error as before), I dug around a bit trying to pass Sequel a logger and found how with config.gateways[:default].use_logger(logger) and it shows that the code executed this:

PRAGMA foreign_keys = 1;
PRAGMA case_sensitive_like = 1;
SELECT sqlite_version();
SELECT * FROM `sqlite_master` WHERE ((`name` != 'sqlite_sequence') AND (`type` = 'table'));
PRAGMA table_info('AgLibraryCollection');

I tried to execute the last command, and... it works:

$ sqlite3 test.db "PRAGMA table_info('AgLibraryCollection')"
0|id_local|INTEGER|0||1
1|creationId||1|''|0
2|genealogy||1|''|0
3|imageCount||0||0
4|name||1|''|0
5|parent|INTEGER|0||0
6|systemOnly||1|''|0

This gets weirder and weirder :o

from rom-sql.

also, you can take a look here: https://github.com/rom-rb/rom-repository/blob/master/examples/sql.rb. One advice with rom-rb, it's always useful to check the tests

from rom-sql.

I find highly unsettling that you can pass an invalid url without issue and the rest of the queries will just happily raise meaningless errors, I suppose it comes directly from sequel and is not in rom but stil annoying.

I fixed the path and my container line now looks like this: rom = ROM.container(:sql, 'sqlite://./test.db') do |config|, I got a new error :p

rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:69:in `block in map_type': Cannot find corresponding type for  (ROM::SQL::UnknownDBTypeError)
	from rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:68:in `fetch'
	from rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:68:in `map_type'
	from rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:56:in `build_type'
	from rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:45:in `block in call'
	from rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:44:in `each'
	from rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:44:in `each_with_object'
	from rom-sql-0.9.1/lib/rom/sql/schema/inferrer.rb:44:in `call'
	from rom-sql-0.9.1/lib/rom/sql/relation.rb:47:in `block (2 levels) in inherited'
	from rom-2.0.2/lib/rom/schema.rb:83:in `finalize!'
	from rom-sql-0.9.1/lib/rom/sql/schema.rb:24:in `finalize!'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:53:in `build_relation'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:25:in `block (2 levels) in run!'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:24:in `each'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:24:in `block in run!'
	from rom-2.0.2/lib/rom/relation_registry.rb:6:in `initialize'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:23:in `new'
	from rom-2.0.2/lib/rom/setup/finalize/finalize_relations.rb:23:in `run!'
	from rom-2.0.2/lib/rom/setup/finalize.rb:93:in `load_relations'
	from rom-2.0.2/lib/rom/setup/finalize.rb:62:in `run!'
	from rom-2.0.2/lib/rom/create_container.rb:35:in `finalize'
	from rom-2.0.2/lib/rom/create_container.rb:13:in `initialize'
	from rom-2.0.2/lib/rom/create_container.rb:54:in `initialize'
	from rom-2.0.2/lib/rom/create_container.rb:59:in `new'
	from rom-2.0.2/lib/rom/create_container.rb:59:in `container'
	from app.rb:10:in `<main>'

@Kukunin I looked at the tests files but it really does not give much more information than what is in the quickstart in the documentation, my comments above also applies to it: it create a memory database, I am opening an existing one, it creates a new schema where I am using an existing one.

from rom-sql.

I find highly unsettling that you can pass an invalid url without issue and the rest of the queries will just happily raise meaningless errors

It's hard to tell but maybe it's a bug in sequel, I would expect to see an error about invalid URI. I just checked and it seems like it created an in-memory sqlite database, just because there's no path in that URI. Something worth reporting to Jeremy I think.

I got a new error :p

Can you try installing beta version of rom and rom-sql and try again? We improved inferrer a lot so it might work. If it doesn't please paste here what rom.gateways[:default].connection.schema(:AgLibraryCollection) returns.

from rom-sql.

I just tried with latest beta:

gem 'rom',              '~> 3.0.0.beta3'
gem 'rom-repository',   '~> 1.0.0.beta2'
gem 'rom-sql',          '~> 1.0.0.beta3'

my script got a little further it seems:

rom-3.0.0.beta3/lib/rom/schema.rb:271:in `finalize!': missing attributes in ROM::Relation::Name(AgLibraryCollection) schema: :creationId, :genealogy, :imageCount, :name, :systemOnly (ROM::Schema::MissingAttributesError)
	from rom-sql-1.0.0.beta3/lib/rom/sql/schema.rb:85:in `finalize!'
	from rom-3.0.0.beta3/lib/rom/setup/finalize/finalize_relations.rb:54:in `build_relation'
	from rom-3.0.0.beta3/lib/rom/setup/finalize/finalize_relations.rb:25:in `block (2 levels) in run!'
	from rom-3.0.0.beta3/lib/rom/setup/finalize/finalize_relations.rb:24:in `each'
	from rom-3.0.0.beta3/lib/rom/setup/finalize/finalize_relations.rb:24:in `block in run!'
	from rom-3.0.0.beta3/lib/rom/relation_registry.rb:6:in `initialize'
	from rom-3.0.0.beta3/lib/rom/setup/finalize/finalize_relations.rb:23:in `new'
	from rom-3.0.0.beta3/lib/rom/setup/finalize/finalize_relations.rb:23:in `run!'
	from rom-3.0.0.beta3/lib/rom/setup/finalize.rb:93:in `load_relations'
	from rom-3.0.0.beta3/lib/rom/setup/finalize.rb:62:in `run!'
	from rom-3.0.0.beta3/lib/rom/create_container.rb:33:in `finalize'
	from rom-3.0.0.beta3/lib/rom/create_container.rb:11:in `initialize'
	from rom-3.0.0.beta3/lib/rom/create_container.rb:52:in `initialize'
	from rom-3.0.0.beta3/lib/rom/create_container.rb:57:in `new'
	from rom-3.0.0.beta3/lib/rom/create_container.rb:57:in `container'
	from app.rb:11:in `<main>'

I don't understand the error, what does missing attributes means in that case ?

PS: As a sidenote if I do require "rom" an exception is raised complaining about uninitialized constant Forwardable, I had to add require 'forwardable' just before it to make it work.

from rom-sql.

my script got a little further it seems:

OK cool, please paste what this returns:

rom.gateways[:default].connection.schema(:AgLibraryCollection)

As a sidenote if I do require "rom" an exception is raised complaining about uninitialized constant Forwardable

Oh nice catch, I'll fix that right away

from rom-sql.

Here is the result:

[
  [:id_local, {
    :allow_null=>true,
    :default=>nil,
    :db_type=>"INTEGER",
    :primary_key=>true,
    :auto_increment=>true,
    :type=>:integer,
    :ruby_default=>nil
  }],
  [:creationId, {
    :allow_null=>false,
    :default=>"''",
    :db_type=>"",
    :primary_key=>false,
    :type=>nil,
    :ruby_default=>nil
  }],
  [:genealogy, {
    :allow_null=>false,
    :default=>"''",
    :db_type=>"",
    :primary_key=>false,
    :type=>nil,
    :ruby_default=>nil
  }],
  [:imageCount, {
    :allow_null=>true,
    :default=>nil,
    :db_type=>"",
    :primary_key=>false,
    :type=>nil,
    :ruby_default=>nil
  }],
  [:name, {
    :allow_null=>false,
    :default=>"''",
    :db_type=>"",
    :primary_key=>false,
    :type=>nil,
    :ruby_default=>nil
  }],
  [:parent, {
    :allow_null=>true,
    :default=>nil,
    :db_type=>"INTEGER",
    :primary_key=>false,
    :type=>:integer,
    :ruby_default=>nil
  }],
  [:systemOnly, {
    :allow_null=>false,
    :default=>"''",
    :db_type=>"",
    :primary_key=>false,
    :type=>nil,
    :ruby_default=>nil
  }]
]

from rom-sql.

from rom-sql.

@flash-gordon ^^ any clue why db_type is set to an empty string?

@schmurfy there's no way to infer these attributes given that sequel returns empty strings for db_type property. Can you show me how this schema was created? For the time being you can define attributes yourself explicitly in the schema block:

schema(:AgLibraryCollection, infer: true) do
  attribute :creationId, Types::Int
  attribute :imageCount, Types::Int
  attribute :name, Types::String
  attribute :genealogy, Types::String # not sure if you want a string here
  attribute :systemOnly, Types::String # same here, not sure if that's supposed to be a string
end

from rom-sql.

@flash-gordon yeah me too, I mean if you look at this:

$ sqlite3 test.db "PRAGMA table_info('AgLibraryCollection')"
0|id_local|INTEGER|0||1
1|creationId||1|''|0
2|genealogy||1|''|0
3|imageCount||0||0
4|name||1|''|0
5|parent|INTEGER|0||0
6|systemOnly||1|''|0

then it's indeed empty, only id_local has INTEGER set the rest is just empty...should we default to String in such case? I've no idea what sqlite is doing under the hood.

UPDATE: and parent has INTEGER

from rom-sql.

from rom-sql.

here is the schema returned using the cli utility and the .schema command:

CREATE TABLE AgLibraryCollection (
    id_local INTEGER PRIMARY KEY,
    creationId NOT NULL DEFAULT '',
    genealogy NOT NULL DEFAULT '',
    imageCount,
    name NOT NULL DEFAULT '',
    parent INTEGER,
    systemOnly NOT NULL DEFAULT ''
);

if I read that well there is no type defined for most of the columns xD

An interesting point here is that my Sequel did manage to infer the schema, maybe you should use string as default if nothing else if defined.

from rom-sql.

@flash-gordon @schmurfy wdyt about adding Types::Object for "who knows what" types? Seems appropriate in this weird sqlite case

from rom-sql.

@solnic yes, that's one option. The other is to return strings, but I'd 👍 for Object type

from rom-sql.

What would the Object solution means, what would it returns ?

from rom-sql.

@schmurfy it would just set attribute primitive type to Object and that's it, since we don't know what it is exactly then it's the only solution we can come up with

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