diff options
Diffstat (limited to 'activerecord/lib/active_record/validations/uniqueness.rb')
| -rw-r--r-- | activerecord/lib/active_record/validations/uniqueness.rb | 88 |
1 files changed, 48 insertions, 40 deletions
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb index bf863c7063..9cd6c26322 100644 --- a/activerecord/lib/active_record/validations/uniqueness.rb +++ b/activerecord/lib/active_record/validations/uniqueness.rb @@ -14,19 +14,23 @@ 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 - sql, params = mount_sql_and_params(finder_class, table_name, attribute, value) + coder = record.class.serialized_attributes[attribute.to_s] - relation = table.where(sql, *params) + if value && coder + value = coder.dump value + end + + sql, params = mount_sql_and_params(finder_class, record.class.quoted_table_name, attribute, value) + + 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 @@ -78,24 +82,29 @@ module ActiveRecord end module ClassMethods - # Validates whether the value of the specified attributes are unique across the system. + # Validates whether the value of the specified attributes are unique across the system. # Useful for making sure that only one user # can be named "davidhh". # # class Person < ActiveRecord::Base - # validates_uniqueness_of :user_name, :scope => :account_id + # validates_uniqueness_of :user_name # end # - # It can also validate whether the value of the specified attributes are unique based on multiple - # scope parameters. For example, making sure that a teacher can only be on the schedule once + # It can also validate whether the value of the specified attributes are unique based on a scope parameter: + # + # class Person < ActiveRecord::Base + # validates_uniqueness_of :user_name, :scope => :account_id + # end + # + # Or even multiple scope parameters. For example, making sure that a teacher can only be on the schedule once # per semester for a particular class. # # class TeacherSchedule < ActiveRecord::Base # validates_uniqueness_of :teacher_id, :scope => [:semester_id, :class_id] # end # - # When the record is created, a check is performed to make sure that no record exists in the database - # with the given value for the specified attribute (that maps to a column). When the record is updated, + # When the record is created, a check is performed to make sure that no record exists in the database + # with the given value for the specified attribute (that maps to a column). When the record is updated, # the same check is made but disregarding the record itself. # # Configuration options: @@ -105,11 +114,11 @@ module ActiveRecord # * <tt>:allow_nil</tt> - If set to true, skips this validation if the attribute is +nil+ (default is +false+). # * <tt>:allow_blank</tt> - If set to true, skips this validation if the attribute is blank (default is +false+). # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should - # occur (e.g. <tt>:if => :allow_validation</tt>, or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>). + # occur (e.g. <tt>:if => :allow_validation</tt>, or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>). # The method, proc or string should return or evaluate to a true or false value. # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should - # not occur (e.g. <tt>:unless => :skip_validation</tt>, or - # <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>). The method, proc or string should + # not occur (e.g. <tt>:unless => :skip_validation</tt>, or + # <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>). The method, proc or string should # return or evaluate to a true or false value. # # === Concurrency and integrity @@ -149,33 +158,32 @@ 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: + # 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 # - # - 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. - # - # 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. + # The bundled ActiveRecord::ConnectionAdapters distinguish unique index + # constraint errors from other types of database errors by throwing an + # ActiveRecord::RecordNotUnique exception. + # For other adapters you will have to parse the (database-specific) exception + # message to detect such a case. + # The following bundled adapters throw the ActiveRecord::RecordNotUnique exception: + # * ActiveRecord::ConnectionAdapters::MysqlAdapter + # * ActiveRecord::ConnectionAdapters::Mysql2Adapter + # * ActiveRecord::ConnectionAdapters::SQLiteAdapter + # * ActiveRecord::ConnectionAdapters::SQLite3Adapter + # * ActiveRecord::ConnectionAdapters::PostgreSQLAdapter # def validates_uniqueness_of(*attr_names) validates_with UniquenessValidator, _merge_attributes(attr_names) |