Given the migration above, you could have multiple users with username bob given the following inserts: ('bob', null), ('bob', null), ('bob', null). We can agree this is not the expected behavior.
Per model:
To avoid this problem, we could use a flag column instead of a datetime, but the datetime value has intrinsic usefulness. Instead, we can add a second column for the unique key that always has a value, in this case 0 or 1:
Support this new column by updating your model as such:
or globally in a rails initializer, e.g. `config/initializer/paranoia.rb`
``` ruby
classClient<ActiveRecord::Base
acts_as_paranoid:flag_column=>:is_deleted
...
end
```ruby
Paranoia.default_sentinel_value=DateTime.new(0)
```
If you create an index on the flag column, and you want paranoia to use that index instead of deleted_at, you can add `:index_column => :is_deleted` to the acts_as_paranoid definition.
ActiveRecord::Base.connection.execute'CREATE TABLE paranoid_model_with_anthor_class_name_belongs (id INTEGER NOT NULL PRIMARY KEY, parent_model_id INTEGER, deleted_at DATETIME, paranoid_model_with_has_one_id INTEGER)'
ActiveRecord::Base.connection.execute'CREATE TABLE paranoid_model_with_foreign_key_belongs (id INTEGER NOT NULL PRIMARY KEY, parent_model_id INTEGER, deleted_at DATETIME, has_one_foreign_key_id INTEGER)'
ActiveRecord::Base.connection.execute'CREATE TABLE featureful_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME, name VARCHAR(32))'
ActiveRecord::Base.connection.execute'CREATE TABLE plain_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME, is_deleted tinyint(1) not null default 0)'
ActiveRecord::Base.connection.execute'CREATE TABLE plain_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
ActiveRecord::Base.connection.execute'CREATE TABLE callback_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
ActiveRecord::Base.connection.execute'CREATE TABLE fail_callback_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
ActiveRecord::Base.connection.execute'CREATE TABLE related_models (id INTEGER NOT NULL PRIMARY KEY, parent_model_id INTEGER NOT NULL, deleted_at DATETIME)'
...
...
@@ -26,6 +26,7 @@ def connect!
ActiveRecord::Base.connection.execute'CREATE TABLE employees (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
ActiveRecord::Base.connection.execute'CREATE TABLE jobs (id INTEGER NOT NULL PRIMARY KEY, employer_id INTEGER NOT NULL, employee_id INTEGER NOT NULL, deleted_at DATETIME)'
ActiveRecord::Base.connection.execute'CREATE TABLE custom_column_models (id INTEGER NOT NULL PRIMARY KEY, destroyed_at DATETIME)'
ActiveRecord::Base.connection.execute'CREATE TABLE custom_sentinel_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME NOT NULL)'
ActiveRecord::Base.connection.execute'CREATE TABLE non_paranoid_models (id INTEGER NOT NULL PRIMARY KEY, parent_model_id INTEGER)'
end
...
...
@@ -160,6 +161,36 @@ class ParanoiaTest < test_framework