diff options
Diffstat (limited to 'activerecord/lib/active_record/validations/uniqueness.rb')
| -rw-r--r-- | activerecord/lib/active_record/validations/uniqueness.rb | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb index 32d17a1392..aa2794f120 100644 --- a/activerecord/lib/active_record/validations/uniqueness.rb +++ b/activerecord/lib/active_record/validations/uniqueness.rb @@ -18,7 +18,11 @@ module ActiveRecord relation = build_relation(finder_class, table, attribute, value) if record.persisted? && finder_class.primary_key.to_s != attribute.to_s - relation = relation.where.not(finder_class.primary_key => record.id) + if finder_class.primary_key + relation = relation.where.not(finder_class.primary_key => record.id) + else + raise UnknownPrimaryKey.new(finder_class, "Can not validate uniqueness for persisted record without primary key.") + end end relation = scope_relation(record, table, relation) relation = relation.merge(options[:conditions]) if options[:conditions] @@ -168,7 +172,8 @@ module ActiveRecord # # === Concurrency and integrity # - # Using this validation method in conjunction with ActiveRecord::Base#save + # Using this validation method in conjunction with + # {ActiveRecord::Base#save}[rdoc-ref:Persistence#save] # does not guarantee the absence of duplicate record insertions, because # uniqueness checks on the application level are inherently prone to race # conditions. For example, suppose that two users try to post a Comment at @@ -205,12 +210,12 @@ module ActiveRecord # This could even happen if you use transactions with the 'serializable' # 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 + # {connection.add_index}[rdoc-ref: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 + # {ActiveRecord::Base#save}[rdoc-ref:Persistence#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 |