Defaults

Defaults are a handy way to avoid typing too much. Defaults are handled by sqlkit.db.defaults.Default class:

from sqlkit.db  import defaults
def_visita = defaults.Defaults('cliente_visita', metadata=db.metadata, local=False)
def_visita.set_defaults( {'data' : def_visita.now, 'telefonata' : True})
def_visita.set_default( title='Write a title...', duration=90)
def_visita.fk('director_id', 'first_name', 'Olmi')

Defaults class requires a table name and a metaclass to know where to autoload/read table definition.

Defaults can be local to a sqlwidget or global to the application.

set_default

The main method is set_defaults that requires a dictionary as argument with field_name as keys and field defaults as value. Alternatively set_default accepts keyword args.

fk

Default in foreign key are set literally via fk. It will follow the reference and find the correct value

now & today

attributes now and today will be substituted appropriately when creating the field

SA defaults & server defaults

At the moment Sqlalchemy defaults are handled only in case of a fixed value (not a callable) nor defaults defined in the server. Adding a new record with an unhandled default will result in an empty value.

Defaults local to the application

Sqlwidgets have an attribute called defaults that is an instance of sqlwidget.db.defaults.Defaults already correctly instantiated that allows to set defaults local only to the instance of sqlwidget they belong to.

You can use such a default in any of the following ways:

m = SqlMask('movie', ...)
m.defaults.set_default(actor=False)
m.defaults.set_defaults( {'title' : 'write your preferred...'} )
m.defaults.fk('director_id', 'first_name', 'Fellini')