NAME¶
Tangram::Type::Dump::Any - Intuitive DataBase InterFace
SYNOPSIS¶
# ... in a nearby Tangram::Schema structure ...
SomeClass =>
{ fields =>
{ idbif => {
-options => { dumper => 'Data::Dumper',
},
some_field => undef,
some_property => undef,
some_attribute => undef,
each_one => undef,
gets => undef,
saved => undef,
},
string => {
cheese => undef,
},
},
};
DESCRIPTION¶
The
idbif mapping type collates multiple data members into a single
perl_dump (see Tangram::Type::Dump::Perl),
storable (see
Tangram::Type::Dump::Storable) or
yaml (see Tangram::Type::Dump::YAML)
column.
For instance, with the schema definition in the example, all the columns in the
example would be serialised via Data::Dumper.
If you stored an object like this:
$cheese = bless { cheese => "gouda",
gets => 6,
each_one => 9 }, "SomeClass";
You would see something in your database similar to:
/^'--v------v--------v----------------------------'^\
| id | type | cheese | idbif |
>----o------o--------o------------------------------<
| 1 | 42 | gouda | { gets => 6, each_one => 9 } |
\_,--^------^--------^----------------------------._/
(note: the actual output from your SQL Database client may differ from the
above)
So, if you're the sort of person who likes to set their attributes with
accessors, but doesn't like the overhead this places on the RDBMS... then this
may help. Note: the real benefits of this mapping type are for when you're
storing more complex data structures than "6" and "9" :-).
You may prefer to use the default dumping type, which is
storable.
LINKS TO OTHER OBJECTS¶
If Tangram encounters another object which
is already in storage (ie, has
been inserted via "$storage->insert($foo)"), then it will store a
"Memento". This memento includes the object ID, which is sensitive
to schema changes (the ordering of classes in the schema).
If the class implements a "px_freeze" and "px_thaw"
function, then there will be a "Memento" that includes the class
name of the object, and the data that was returned by the class'
"px_freeze" method. To be reconstituted, it is called as:
SomeClass->px_thaw(@data)
See Tangram::Type::Dump for more details on the complicity API.
Please set RETVAL to be the thawed object. (that is, return a single scalar).
BUT, I REALLY, REALLY HATE SCHEMAS!¶
However, maybe you are one of those folk who don't like to declare their
attributes, instead peppering hashes willy nilly, then there is another
option.
Instead of explicitly listing the fields you want, if you don't specify any
fields at all, then it means save ALL remaining fields into the column. For
convenience, "-poof" is provided as a synonym for
"-options", so you can write:
{ fields =>
{ idbif => { -poof => # There goes another one!
{
},
}
},
}
[ You see, Tangram::Type::Dump::Any isn't actually an intuitive DB interface.
No, an intuitive DB interface is a user interface component, and that title is
reserved for Visual Tangram. VT expects to pick up the title with any luck by
the end of the 21st century^W RSN!
I Don't Believe In Fairies is actually what it stands for. It's a completely
arbitrary name; chosen for no reason at all, and certainly not anything to do
with Pixie. ]