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Diffstat (limited to 'guides/source/active_record_validations.md')
-rw-r--r-- | guides/source/active_record_validations.md | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md index efa826e8df..a483a6dd24 100644 --- a/guides/source/active_record_validations.md +++ b/guides/source/active_record_validations.md @@ -575,7 +575,9 @@ This helper validates that the attribute's value is unique right before the object gets saved. It does not create a uniqueness constraint in the database, so it may happen that two different database connections create two records with the same value for a column that you intend to be unique. To avoid that, -you must create a unique index in your database. +you must create a unique index on both columns in your database. See +[the MySQL manual](http://dev.mysql.com/doc/refman/5.6/en/multiple-column-indexes.html) +for more details about multiple column indexes. ```ruby class Account < ActiveRecord::Base @@ -616,10 +618,6 @@ The default error message is _"has already been taken"_. This helper passes the record to a separate class for validation. ```ruby -class Person < ActiveRecord::Base - validates_with GoodnessValidator -end - class GoodnessValidator < ActiveModel::Validator def validate(record) if record.first_name == "Evil" @@ -627,6 +625,10 @@ class GoodnessValidator < ActiveModel::Validator end end end + +class Person < ActiveRecord::Base + validates_with GoodnessValidator +end ``` NOTE: Errors added to `record.errors[:base]` relate to the state of the record @@ -644,10 +646,6 @@ Like all other validations, `validates_with` takes the `:if`, `:unless` and validator class as `options`: ```ruby -class Person < ActiveRecord::Base - validates_with GoodnessValidator, fields: [:first_name, :last_name] -end - class GoodnessValidator < ActiveModel::Validator def validate(record) if options[:fields].any?{|field| record.send(field) == "Evil" } @@ -655,6 +653,10 @@ class GoodnessValidator < ActiveModel::Validator end end end + +class Person < ActiveRecord::Base + validates_with GoodnessValidator, fields: [:first_name, :last_name] +end ``` Note that the validator will be initialized *only once* for the whole application |