On Saturday, May 14, 2011 5:37:39 PM UTC-4, 黄祥 wrote: > > hi, > > is there anyone can explain about the usage of default? > > e.g. on http://web2py.com/book/default/chapter/03#Adding-CRUD > db.comment.image_id.default = image.id
You can read about it here: http://web2py.com/book/default/chapter/06#Record-Representation It sets the default value for a field for when an insert is done without specifying any value, and it is also used to pre-populate SQLFORM fields. You can specify it when you define your table, but you can also change it at other points in your code (e.g., you may specify a default where the table is defined in your model file, but then later change the default in a controller function). In the example above, it looks like it's being used to pre-populate the crud form with the currently selected image. Anthony
