I've not looked at the source code to Alzabo or DBIx::DBSchema but
perhaps it would be possible to define a base class that uses DBI
functions to get the meta-data. The DB specific stuff could be done
with overridden methods?
Personally, I believe there should be more meta-data methods in DBI than
currently exist. Perhaps there could even be a $dbh->supports() method
that indiciated the level of compliance.
Also, there could be some standardisation on what is returned by the
meta-data methods: currently methods like table_info() use different
column names depending on the DBD in question and also use different
qualifiers, for example table() may or may not include the owner or
catalog name with the table.
I would like to see an object orientated approach that provides methods
for accessing the meta-data, something like:
my $dbs = $dbh->schema();
my $tables = $dbs->tables();
foreach my $table (@{$tables}) {
print $table->owner, ".", $table->name, ":\n";
foreach my $index (@{$table->indexes}) {
print "\t", $index->name, ":\n";
foreach my $column (@{$index->columns}) {
print "\t\t", $column->name, " (", $column->domain, ")\n";
}
}
}
This sounds like a big job but I guess that much of the DB specific hard
work has been done by the authors of Alzabo and DBIx::DBSchema. This
could be moved into the DBD or perhaps an associated package
(DBD::ODBC::Schema for example which would be a subclass of DBD::Schema).
Initially the schema object would be read-only but as things develop it
could be made read-write.
--
Simon Oliver
