Unrestrict primary key
Category.create id: 'travel' # error
Category.unrestrict_primary_key
Category.create id: 'travel' # ok
Schema
class Deal < Sequel::Model
set_schema do
primary_key :id
primary_key [:id, :title]
String :name, primary_key: true
String :title
Numeric :price
DateTime :expires
unique :whatever
check(:price) { num > 0 }
foreign_key :artist_id
String :artist_name, key: :id
index :title
index [:artist_id, :name]
full_text_index :title
# String, Integer, Fixnum, Bignum, Float, Numeric, BigDecimal,
# Date, DateTime, Time, File, TrueClass, FalseClass
end
end
Callbacks
before_create
after_create
before_validation
after_validation
before_save
before_update
UPDATE QUERY
after_update
after_save
before_destroy
DELETE QUERY
after_destroy
Model stuff
deal = Deal[1]
deal.changed_columns
deal.destroy # Calls hooks
deal.delete # No hooks
deal.exists?
deal.new?
deal.hash # Only uniques
deal.keys #=> [:id, :name]
deal.modified!
deal.modified?
deal.lock!
Validations
def validate
super
errors.add(:name, 'cannot be empty') if !name || name.empty?
validates_presence [:title, :site]
validates_unique :name
validates_format /\Ahttps?:\/\//, :website, :message=>'is not a valid URL'
validates_includes %w(a b c), :type
validates_integer :rating
validates_numeric :number
validates_type String, [:title, :description]
validates_integer :rating if new?
# options: :message =>, :allow_nil =>, :allow_blank =>,
# :allow_missing =>,
validates_exact_length 17, :isbn
validates_min_length 3, :name
validates_max_length 100, :name
validates_length_range 3..100, :name
# Setter override
def filename=(name)
@values[:filename] = name
end
end
end
deal.errors
Model associations
class Deal < Sequel::Model
# Us (left) <=> Them (right)
many_to_many :images,
left_id: :deal_id,
right_id: :image_id,
join_table: :image_links
one_to_many :files,
key: :deal_id,
class: :DataFile,
many_to_one :parent, class: self
one_to_many :children, key: :parent_id, class: self
one_to_many :gold_albums, class: :Album do |ds|
ds.filter { copies_sold > 50000 }
end
Provided by many_to_many
Deal[1].images
Deal[1].add_image
Deal[1].remove_image
Deal[1].remove_all_images
Alter table
database.alter_table :deals do
add_column :name, String
drop_column :column_name
rename_column :from, :to
add_constraint :valid_name, :name.like('A%')
drop_constraint :constraint
add_full_text_index :body
add_spacial_index [columns]
add_index :price
drop_index :index
add_foreign_key :artist_id, :table
add_primary_key :id
add_unique_constraint [columns]
set_column_allow_null :foo, false
set_column_default :title, ''
set_column_type :price, 'char(10)'
end
Documents
http://sequel.rubyforge.org/rdoc/files/doc/association_basics_rdoc.html
http://sequel.rubyforge.org/rdoc/classes/Sequel/Schema/Generator.html
http://sequel.rubyforge.org/rdoc/files/doc/validations_rdoc.html
http://sequel.rubyforge.org/rdoc/classes/Sequel/Model.html
Miscellaneous:
dataset.sql # "SELECT * FROM items"
dataset.delete_sql # "DELETE FROM items"
dataset.where(:name => 'sequel').exists # "EXISTS ( SELECT * FROM items WHERE name = 'sequel' )"
dataset.columns #=> array of columns in the result set, does a SELECT
DB.schema(:items) => [[:id, {:type=>:integer, ...}], [:name, {:type=>:string, ...}], ...]
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Transactions
DB.transaction do
dataset.insert(:first_name => 'Inigo', :last_name => 'Montoya')
dataset.insert(:first_name => 'Farm', :last_name => 'Boy')
end # Either both are inserted or neither are inserted
Database#transaction is re-entrant:
DB.transaction do # BEGIN issued only here
DB.transaction
dataset << {:first_name => 'Inigo', :last_name => 'Montoya'}
end
end # COMMIT issued only here
Transactions are aborted if an error is raised:
DB.transaction do
raise "some error occurred"
end # ROLLBACK issued and the error is re-raised
Transactions can also be aborted by raising Sequel::Rollback:
DB.transaction do
raise(Sequel::Rollback) if something_bad_happened
end # ROLLBACK issued and no error raised
Savepoints can be used if the database supports it:
DB.transaction do
dataset << {:first_name => 'Farm', :last_name => 'Boy'} # Inserted
DB.transaction(:savepoint=>true) # This savepoint is rolled back
dataset << {:first_name => 'Inigo', :last_name => 'Montoya'} # Not inserted
raise(Sequel::Rollback) if something_bad_happened
end
dataset << {:first_name => 'Prince', :last_name => 'Humperdink'} # Inserted
end
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