Module | Sequel::Plugins::MssqlOptimisticLocking |
In: |
lib/sequel/plugins/mssql_optimistic_locking.rb
|
This plugin implements optimistic locking mechanism on Microsoft SQL Server using a timestamp/rowversion column to ensure that concurrent updates are detected and previous changes are not automatically overridden. This is best implemented by a code example:
class Person < Sequel::Model plugin :mssql_optimistic_locking end p1 = Person[1] p2 = Person[1] p1.update(:name=>'Jim') # works p2.update(:name=>'Bob') # raises Sequel::NoExistingObject
In order for this plugin to work, you need to make sure that the database table has a column of timestamp or rowversion. The plugin uses a default name of timestamp for this columns, but you can override that using the :lock_column option:
plugin :mssql_optimistic_locking, :lock_column=>:column_name
This plugin relies on the instance_filters plugin.
Load the instance_filters plugin into the model.
# File lib/sequel/plugins/mssql_optimistic_locking.rb, line 28 28: def self.apply(model, opts=OPTS) 29: model.plugin :instance_filters 30: end