Persephone is a two part framework. The first part is where you describe your schema and features, which will be processed by Persephone. Code will be generated by this step for you to use in your target language (PHP for now). more⇛

When loading an entity from the DB, you may get this error message 'Attempt to set null on non-nullable field' (DBS_SetFieldExcpetion::TYPE_NULL) if the DB column produces null and your entity is not marked with ALLOW_NULL. more⇛

Where possible Date and DateTime field types will be represented using an appropriate Date type in the native language. This will not normally be an integer timestamp, as that range is limited. more⇛

The 'Field not available on this instance:field' is a common one and can have several different meanings. It is unfortunately not easy, or possible, for Persephone to determine exactly why the field is not available. more⇛