package DBIx::DBSchema::DBD;
use strict;
use vars qw($VERSION);
$VERSION = '0.04';
=head1 NAME
DBIx::DBSchema::DBD - DBIx::DBSchema Driver Writer's Guide and Base Class
=head1 SYNOPSIS
perldoc DBIx::DBSchema::DBD
package DBIx::DBSchema::DBD::FooBase
use DBIx::DBSchema::DBD;
@ISA = qw(DBIx::DBSchema::DBD);
=head1 DESCRIPTION
Drivers should be named DBIx::DBSchema::DBD::DatabaseName, where DatabaseName
is the same as the DBD:: driver for this database. Drivers should implement the
following class methods:
=over 4
=item columns CLASS DBI_DBH TABLE
Given an active DBI database handle, return a listref of listrefs (see
L<perllol>), each containing six elements: column name, column type,
nullability, column length, column default, and a field reserved for
driver-specific use.
=item column CLASS DBI_DBH TABLE COLUMN
Same as B<columns> above, except return the listref for a single column. You
can inherit from DBIx::DBSchema::DBD to provide this function.
=cut
sub column {
my($proto, $dbh, $table, $column) = @_;
#@a = grep { $_->[0] eq $column } @{ $proto->columns( $dbh, $table ) };
#$a[0];
@{ [
grep { $_->[0] eq $column } @{ $proto->columns( $dbh, $table ) }
] }[0]; #force list context on grep, return scalar of first element
}
=item primary_key CLASS DBI_DBH TABLE
Given an active DBI database handle, return the primary key for the specified
table.
=item unique CLASS DBI_DBH TABLE
Deprecated method - see the B<indices> method for new drivers.
Given an active DBI database handle, return a hashref of unique indices. The
keys of the hashref are index names, and the values are arrayrefs which point
a list of column names for each. See L<perldsc/"HASHES OF LISTS"> and
L<DBIx::DBSchema::Index>.
=item index CLASS DBI_DBH TABLE
Deprecated method - see the B<indices> method for new drivers.
Given an active DBI database handle, return a hashref of (non-unique) indices.
The keys of the hashref are index names, and the values are arrayrefs which
point a list of column names for each. See L<perldsc/"HASHES OF LISTS"> and
L<DBIx::DBSchema::Index>.
=item indices CLASS DBI_DBH TABLE
Given an active DBI database handle, return a hashref of all indices, both
unique and non-unique. The keys of the hashref are index names, and the values
are again hashrefs with the following keys:
=over 8
=item name - Index name (redundant)
=item using - Optional index method
=item unique - Boolean indicating whether or not this is a unique index
=item columns - List reference of column names (or expressions)
=back
(See L<FS::DBIx::DBSchema::Index>)
New drivers are advised to implement this method, and existing drivers are
advised to (eventually) provide this method instead of B<index> and B<unique>.
For backwards-compatibility with current drivers, the base DBIx::DBSchema::DBD
class provides an B<indices> method which uses the old B<index> and B<unique>
methods to provide this data.
=cut
sub indices {
#my($proto, $dbh, $table) = @_;
my($proto, @param) = @_;
my $unique_hr = $proto->unique( @param );
my $index_hr = $proto->index( @param );
scalar(
{
(
map {
$_ => { 'name' => $_,
'unique' => 1,
'columns' => $unique_hr->{$_},
},
}
keys %$unique_hr
),
(
map {
$_ => { 'name' => $_,
'unique' => 0,
'columns' => $index_hr->{$_},
},
}
keys %$index_hr
),
}
);
}
=item default_db_catalog
Returns the default database catalog for the DBI table_info command.
Inheriting from DBIx::DBSchema::DBD will provide the default empty string.
=cut
sub default_db_catalog { ''; }
=item default_db_catalog
Returns the default database schema for the DBI table_info command.
Inheriting from DBIx::DBSchema::DBD will provide the default empty string.
=cut
sub default_db_schema { ''; }
=back
=head1 TYPE MAPPING
You can define a %typemap array for your driver to map "standard" data
types to database-specific types. For example, the MySQL TIMESTAMP field
has non-standard auto-updating semantics; the MySQL DATETIME type is
what other databases and the ODBC standard call TIMESTAMP, so one of the
entries in the MySQL %typemap is:
'TIMESTAMP' => 'DATETIME',
Another example is the Pg %typemap which maps the standard types BLOB and
LONG VARBINARY to the Pg-specific BYTEA:
'BLOB' => 'BYTEA',
'LONG VARBINARY' => 'BYTEA',
Make sure you use all uppercase-keys.
=head1 AUTHOR
Ivan Kohler <ivan-dbix-dbschema@420.am>
=head1 COPYRIGHT
Copyright (c) 2000-2005 Ivan Kohler
All rights reserved.
This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
=head1 BUGS
=head1 SEE ALSO
L<DBIx::DBSchema>, L<DBIx::DBSchema::DBD::mysql>, L<DBIx::DBSchema::DBD::Pg>,
L<DBIx::DBSchema::Index>, L<DBI>, L<DBI::DBD>, L<perllol>,
L<perldsc/"HASHES OF LISTS">
=cut
1;