A data mapping abstraction over the AWS SDK for Ruby's client for Amazon DynamoDB.
This library is currently under development. More features will be added as we approach general availability, and while our initial release has as small of an API surface area as possible, the interface may change before the GA release.
We would like to invite you to be a part of the ongoing development of this gem. We welcome your contributions, and would also be happy to hear from you about how you would like to use this gem. Feature requests are welcome.
Aws::Record
is available as the aws-record
gem from RubyGems.
gem install 'aws-record'
gem 'aws-record', '~> 2.0'
This automatically includes a dependency on the aws-sdk-dynamodb
gem (part of the modular version-3 of
the AWS SDK for Ruby. If you need to pin to a specific version,
you can add aws-sdk-dynamodb
or aws-sdk-core gem in your
Gemfile.
To create a model that uses aws-record
features, simply include the provided
module:
class MyModel
include Aws::Record
end
You can then specify attributes using the aws-record
DSL:
class MyModel
include Aws::Record
integer_attr :id, hash_key: true
string_attr :name, range_key: true
boolean_attr :active, database_attribute_name: 'is_active_flag'
end
If a matching table does not exist in DynamoDB, you can use the TableConfig DSL to create your table:
cfg = Aws::Record::TableConfig.define do |t|
t.model_class(MyModel)
t.read_capacity_units(5)
t.write_capacity_units(2)
end
cfg.migrate!
With a table in place, you can then use your model class to manipulate items in your table:
item = MyModel.find(id: 1, name: 'Hello Record')
item.active = true
item.save
item.delete!
MyModel.find(id: 1, name: 'Hello Record') # => nil
item = MyModel.new
item.id = 2
item.name = 'Item'
item.active = false
item.save
You can use item operations on your model class to read and manipulate item(s).
More info under following documentation:
Example usage
class MyModel
include Aws::Record
integer_attr :uuid, hash_key: true
string_attr :name, range_key: true
integer_attr :age
end
item = MyModel.find(id: 1, name: 'Foo')
item.update(id: 1, name: 'Foo', age: 1)
Aws Record provides BatchGetItem and BatchWriteItem support for aws-record models.
More info under the following documentation:
See examples below to see the feature in action.
BatchGetItem
Example
class Lunch
include Aws::Record
integer_attr :id, hash_key: true
string_attr :name, range_key: true
end
class Dessert
include Aws::Record
integer_attr :id, hash_key: true
string_attr :name, range_key: true
end
# batch operations
operation = Aws::Record::Batch.read do |db|
db.find(Lunch, id: 1, name: 'Papaya Salad')
db.find(Lunch, id: 2, name: 'BLT Sandwich')
db.find(Dessert, id: 1, name: 'Apple Pie')
end
# BatchRead is enumerable and handles pagination
operation.each { |item| item.id }
# Alternatively, BatchRead provides a lower level interface
# through: execute!, complete? and items.
# Unprocessed items can be processed by calling:
operation.execute! until operation.complete?
BatchWriteItem
Example
class Breakfast
include Aws::Record
integer_attr :id, hash_key: true
string_attr :name, range_key: true
string_attr :body
end
# setup
eggs = Breakfast.new(id: 1, name: 'eggs').save!
waffles = Breakfast.new(id: 2, name: 'waffles')
pancakes = Breakfast.new(id: 3, name: 'pancakes')
# batch operations
operation = Aws::Record::Batch.write(client: Breakfast.dynamodb_client) do |db|
db.put(waffles)
db.delete(eggs)
db.put(pancakes)
end
# unprocessed items can be retried by calling Aws::Record::BatchWrite#execute!
operation.execute! until operation.complete?
Aws Record provides TransactGetItems and TransactWriteItems support for aws-record models.
More info under the Transactions documentation.
See examples below to see the feature in action.
TransactGetItems
Example
class TableOne
include Aws::Record
string_attr :uuid, hash_key: true
end
class TableTwo
include Aws::Record
string_attr :hk, hash_key: true
string_attr :rk, range_key: true
end
results = Aws::Record::Transactions.transact_find(
transact_items: [
TableOne.tfind_opts(key: { uuid: 'uuid1234' }),
TableTwo.tfind_opts(key: { hk: 'hk1', rk: 'rk1'}),
TableTwo.tfind_opts(key: { hk: 'hk2', rk: 'rk2'})
]
) # => results.responses contains nil or marshalled items
results.responses.map { |r| r.class } # [TableOne, TableTwo, TableTwo]
TransactWriteItems
Example
# same models as `TransactGetItems` Example
check_exp = TableOne.transact_check_expression(
key: { uuid: 'foo' },
condition_expression: 'size(#T) <= :v',
expression_attribute_names: {
'#T' => 'body'
},
expression_attribute_values: {
':v' => 1024
}
)
new_item = TableTwo.new(hk: 'hk1', rk: 'rk1', body: 'Hello!')
update_item_1 = TableOne.find(uuid: 'bar')
update_item_1.body = 'Updated the body!'
put_item = TableOne.new(uuid: 'foobar', body: 'Content!')
update_item_2 = TableTwo.find(hk: 'hk2', rk: 'rk2')
update_item_2.body = 'Update!'
delete_item = TableOne.find(uuid: 'to_be_deleted')
Aws::Record::Transactions.transact_write(
transact_items: [
{ check: check_exp },
{ save: new_item },
{ save: update_item_1 },
{
put: put_item,
condition_expression: 'attribute_not_exists(#H)',
expression_attribute_names: { '#H' => 'uuid' },
return_values_on_condition_check_failure: 'ALL_OLD'
},
{ update: update_item_2 },
{ delete: delete_item }
]
)
Aws Record models can be extended using standard ruby inheritance. The child model must
include Aws::Record
in their model and the following will be inherited:
- set_table_name
- Attributes and Keys
- Mutation Tracking:
- local_secondary_indexes
- global_secondary_indexes
- configure_client
See example below to see the feature in action.
class Animal
include Aws::Record
string_attr :name, hash_key: true
integer_attr :age
end
class Dog < Animal
include Aws::Record
boolean_attr :family_friendly
end
dog = Dog.find(name: 'Sunflower')
dog.age = 3
dog.family_friendly = true