diff options
Diffstat (limited to 'activerecord/lib/active_record/validations/uniqueness.rb')
| -rw-r--r-- | activerecord/lib/active_record/validations/uniqueness.rb | 51 |
1 files changed, 20 insertions, 31 deletions
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb index cb1d2ae421..853808eebf 100644 --- a/activerecord/lib/active_record/validations/uniqueness.rb +++ b/activerecord/lib/active_record/validations/uniqueness.rb @@ -14,24 +14,21 @@ module ActiveRecord def validate_each(record, attribute, value) finder_class = find_finder_class_for(record) - table = finder_class.unscoped - - table_name = record.class.quoted_table_name if value && record.class.serialized_attributes.key?(attribute.to_s) value = YAML.dump value end - sql, params = mount_sql_and_params(finder_class, table_name, attribute, value) + sql, params = mount_sql_and_params(finder_class, record.class.quoted_table_name, attribute, value) - relation = table.where(sql, *params) + relation = finder_class.unscoped.where(sql, *params) Array.wrap(options[:scope]).each do |scope_item| scope_value = record.send(scope_item) relation = relation.where(scope_item => scope_value) end - unless record.new_record? + if record.persisted? # TODO : This should be in Arel relation = relation.where("#{record.class.quoted_table_name}.#{record.class.primary_key} <> ?", record.send(:id)) end @@ -154,33 +151,25 @@ module ActiveRecord # | # title! # # This could even happen if you use transactions with the 'serializable' - # isolation level. There are several ways to get around this problem: - # - # - By locking the database table before validating, and unlocking it after - # saving. However, table locking is very expensive, and thus not - # recommended. - # - By locking a lock file before validating, and unlocking it after saving. - # This does not work if you've scaled your Rails application across - # multiple web servers (because they cannot share lock files, or cannot - # do that efficiently), and thus not recommended. - # - Creating a unique index on the field, by using - # ActiveRecord::ConnectionAdapters::SchemaStatements#add_index. In the - # rare case that a race condition occurs, the database will guarantee - # the field's uniqueness. + # isolation level. The best way to work around this problem is to add a unique + # index to the database table using + # ActiveRecord::ConnectionAdapters::SchemaStatements#add_index. In the + # rare case that a race condition occurs, the database will guarantee + # the field's uniqueness. # - # When the database catches such a duplicate insertion, - # ActiveRecord::Base#save will raise an ActiveRecord::StatementInvalid - # exception. You can either choose to let this error propagate (which - # will result in the default Rails exception page being shown), or you - # can catch it and restart the transaction (e.g. by telling the user - # that the title already exists, and asking him to re-enter the title). - # This technique is also known as optimistic concurrency control: - # http://en.wikipedia.org/wiki/Optimistic_concurrency_control + # When the database catches such a duplicate insertion, + # ActiveRecord::Base#save will raise an ActiveRecord::StatementInvalid + # exception. You can either choose to let this error propagate (which + # will result in the default Rails exception page being shown), or you + # can catch it and restart the transaction (e.g. by telling the user + # that the title already exists, and asking him to re-enter the title). + # This technique is also known as optimistic concurrency control: + # http://en.wikipedia.org/wiki/Optimistic_concurrency_control # - # Active Record currently provides no way to distinguish unique - # index constraint errors from other types of database errors, so you - # will have to parse the (database-specific) exception message to detect - # such a case. + # Active Record currently provides no way to distinguish unique + # index constraint errors from other types of database errors, so you + # will have to parse the (database-specific) exception message to detect + # such a case. # def validates_uniqueness_of(*attr_names) validates_with UniquenessValidator, _merge_attributes(attr_names) |