I'm trying to get to grips with the rom-rb persistence library, using sqlite3.
I ran the following migration, which includes a NOT NULL constraint:
ROM::SQL.migration do
change do
create_table :users do
primary_key :id
column :name, String, null: false
column :age, Integer
column :is_admin, TrueClass
end
end
end
Here's my simple app.rb:
require 'rom'
rom = ROM.container(:sql, 'sqlite://db/my-db-file.db') do |config|
class Users < ROM::Relation[:sql]
schema(infer: true)
end
config.relation(:users)
end
users = rom.relations[:users]
puts users.to_a.inspect # => []
create_user = users.command(:create)
create_user.call( name: 'Rob', age: 30, is_admin: true )
puts users.to_a.inspect # never reached
Trying to run this script produced the following output:
Roberts-MacBook-Pro:my-rom-demo Rob$ ruby app.rb
[]
/Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sqlite3-1.3.13/lib/sqlite3/statement.rb:108:in `step': SQLite3::ConstraintException: NOT NULL constraint failed: users.name (ROM::SQL::NotNullConstraintError)
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sqlite3-1.3.13/lib/sqlite3/statement.rb:108:in `block in each'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sqlite3-1.3.13/lib/sqlite3/statement.rb:107:in `loop'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sqlite3-1.3.13/lib/sqlite3/statement.rb:107:in `each'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sqlite3-1.3.13/lib/sqlite3/database.rb:156:in `to_a'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sqlite3-1.3.13/lib/sqlite3/database.rb:156:in `block in execute'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sqlite3-1.3.13/lib/sqlite3/database.rb:95:in `prepare'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sqlite3-1.3.13/lib/sqlite3/database.rb:137:in `execute'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/adapters/sqlite.rb:189:in `block (2 levels) in _execute'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/database/logging.rb:38:in `log_connection_yield'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/adapters/sqlite.rb:189:in `block in _execute'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/database/connecting.rb:253:in `block in synchronize'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/connection_pool/threaded.rb:91:in `hold'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/database/connecting.rb:253:in `synchronize'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/adapters/sqlite.rb:180:in `_execute'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/adapters/sqlite.rb:146:in `execute_insert'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/dataset/actions.rb:1099:in `execute_insert'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/sequel-5.11.0/lib/sequel/dataset/actions.rb:399:in `insert'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/rom-sql-2.5.0/lib/rom/sql/relation/writing.rb:39:in `insert'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/rom-sql-2.5.0/lib/rom/sql/commands/create.rb:46:in `block in insert'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/rom-sql-2.5.0/lib/rom/sql/commands/create.rb:46:in `map'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/rom-sql-2.5.0/lib/rom/sql/commands/create.rb:46:in `insert'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/rom-sql-2.5.0/lib/rom/sql/commands/create.rb:31:in `execute'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/rom-core-4.2.1/lib/rom/command.rb:280:in `call'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/rom-sql-2.5.0/lib/rom/sql/commands/error_wrapper.rb:16:in `call'
from /Rob.rvm/gems/ruby-2.4.0@learn-rails/gems/rom-core-4.2.1/lib/rom/commands/composite.rb:17:in `call'
from app.rb:15:in `<main>'
Why does it think my name attribute is null when I'm providing it?
NOTE: I revised my answer after some testing and learning about ops gem versions
The reason you're getting a NULL CONSTRAINT error is because ROM does not
have a schema loaded for the the users table.
When you defined the container below
rom = ROM.container(:sql, 'sqlite://db/my-db-file.db') do |config|
class Users < ROM::Relation[:sql]
schema(infer: true)
end
config.relation(:users)
end
you defined two things, a relation class bound to a constant called Users and an auto generated relation with the same name but is actually registered inside the ROM container. Effectively the Users constant relation is being ignored. The reason this is important is because the auto generated relation isn't automatically inferring the schema from the database so when you go to write data out, the schema forces all of the unknown keys to be removed causing the error. All you're sending to the db is {}.
To fix the error just tell the relation to infer the schema - an example can be seen below.
require 'rom'
require 'rom/sql'
require 'sqlite3'
puts "ROM Version #{ROM::Core::VERSION}" # 4.2.1
puts "ROM Version #{ROM::SQL::VERSION}" # 2.5.0
puts "Sequel Version #{Sequel::VERSION}" # 5.11.0
puts "SQLite3 Gem Version #{SQLite3::VERSION}" # 1.3.13
opts = {
adapter: :sqlite,
database: 'c:/mydb.db'
}
rom = ROM.container(:sql, opts) do |c|
# Just another way to write the same users table
# c.gateways[:default].create_table(:users) do
# column :id, :integer, primary_key: true
# column :name, :string, null: false
# column :age, :integer
# column :is_admin, :bool
# end
c.gateways[:default].create_table :users do
primary_key :id
column :name, String, null: false
column :age, Integer
column :is_admin, TrueClass
end
c.relation(:users) do
schema(infer: true)
end
end
users = rom.relations[:users]
puts users.to_a.inspect # => []
create_user = users.command(:create)
create_user.call(name: 'Rob', age: 30, is_admin: true)
puts users.to_a.inspect # never reached
# Uncomment if you want to see the users schema
# puts users.dataset.db.schema(:users)
If you want to use standalone relation classes instead of the container config dsl then I suggest reading up on the Auto Registration system.
DATABASE CREATION ISSUE
There is a whole host of things that could be going on which could prevent a sqlite database from being created.
file:// in your paths) [see sqlite docs]My advice here is when working with sqlite and ROM, use the opts hash example from the script above and try and use a relative path from the current working directory. That seems to always work.