SQL » Commands
SQL commands support all features of the standard ROM command API. In addition, the following SQL-specific features are supported:
- The
associatesplugin, for connecting foreign key values when composing commands - The
transactioninterface, which provides a block scope for working with database transactions
Custom commands
Define custom commands only when repositories with changesets and auto-commands are blocking you
Associates Plugin
The associates plugin is used to automatically set foreign-key values when
using command composition.
class CreateTask < ROM::Commands::Create[:sql]
relation :tasks
register_as :create
result :one
associates :user, key: [:user_id, :id]
end
class CreateUser < ROM::Commands::Create[:sql]
relation :users
register_as :create
result :one
end
# using command composition
create_user = rom.command(:users).create
create_task = rom.command(:tasks).create
command = create_user.with(name: 'Jane') >> create_task.with(title: 'Task')
command.call
# using a graph
command = rom.command([
{ user: :users }, [:create, [{ task: :tasks }, [:create]]]
])
command.call user: { name: 'Jane', task: { title: 'Task' } }