[dbsrgits/SQL-Translator.git] / lib / SQL / Translator / Schema.pm

package SQL::Translator::Schema;

# ----------------------------------------------------------------------
# $Id: Schema.pm,v 1.6 2003-06-09 04:18:23 kycl4rk Exp $
# ----------------------------------------------------------------------
# Copyright (C) 2003 Ken Y. Clark <kclark@cpan.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; version 2.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
# 02111-1307  USA
# -------------------------------------------------------------------

=pod

=head1 NAME

SQL::Translator::Schema - SQL::Translator schema object

=head1 SYNOPSIS

  use SQL::Translator::Schema;
  my $schema = SQL::Translator::Schema->new;
  my $table  = $schema->add_table( name => 'foo' );
  my $view   = $schema->add_view( name => 'bar', sql => '...' );

=head1 DESCSIPTION

C<SQL::Translator::Schema> is the object that accepts, validates, and
returns the database structure.

=head1 METHODS

=cut

use strict;
use Class::Base;
use SQL::Translator::Schema::Constants;
use SQL::Translator::Schema::Table;
use SQL::Translator::Schema::View;

use base 'Class::Base';
use vars qw[ $VERSION $TABLE_ORDER $VIEW_ORDER ];

$VERSION = 1.00;

# ----------------------------------------------------------------------
sub init {

=pod

=head2 new

Object constructor.

  my $schema   =  SQL::Translator->new(
      name     => 'Foo',
      database => 'MySQL',
  );

=cut

    my ( $self, $config ) = @_;
    $self->params( $config, qw[ name database ] ) || return undef;
    return $self;
}

# ----------------------------------------------------------------------
sub add_table {

=pod

=head2 add_table

Add a table object.  Returns the new SQL::Translator::Schema::Table object.
The "name" parameter is required.  If you try to create a table with the
same name as an existing table, you will get an error and the table will 
not be created.

  my $t1 = $schema->add_table( name => 'foo' ) or die $schema->error;
  my $t2 = SQL::Translator::Schema::Table->new( name => 'bar' );
  $t2    = $schema->add_table( $table_bar ) or die $schema->error;

=cut

    my $self        = shift;
    my $table_class = 'SQL::Translator::Schema::Table';
    my $table;

    if ( UNIVERSAL::isa( $_[0], $table_class ) ) {
        $table = shift;
        $table->schema( $self );
    }
    else {
        my %args = @_;
        $args{'schema'} = $self;
        $table = $table_class->new( \%args ) or return 
            $self->error( $table_class->error );
    }

    $table->order( ++$TABLE_ORDER );
    my $table_name = $table->name or return $self->error('No table name');

    if ( defined $self->{'tables'}{ $table_name } ) {
        return $self->error(qq[Can't create table: "$table_name" exists]);
    }
    else {
        $self->{'tables'}{ $table_name } = $table;
    }

    return $table;
}

# ----------------------------------------------------------------------
sub add_view {

=pod

=head2 add_view

Add a view object.  Returns the new SQL::Translator::Schema::View object.
The "name" parameter is required.  If you try to create a view with the
same name as an existing view, you will get an error and the view will 
not be created.

  my $v1 = $schema->add_view( name => 'foo' );
  my $v2 = SQL::Translator::Schema::View->new( name => 'bar' );
  $v2    = $schema->add_view( $view_bar ) or die $schema->error;

=cut

    my $self        = shift;
    my $view_class = 'SQL::Translator::Schema::View';
    my $view;

    if ( UNIVERSAL::isa( $_[0], $view_class ) ) {
        $view = shift;
    }
    else {
        my %args = @_;
        return $self->error('No view name') unless $args{'name'};
        $view = $view_class->new( \%args ) or return $view_class->error;
    }

    $view->order( ++$VIEW_ORDER );
    my $view_name = $view->name or return $self->error('No view name');

    if ( defined $self->{'views'}{ $view_name } ) { 
        return $self->error(qq[Can't create view: "$view_name" exists]);
    }
    else {
        $self->{'views'}{ $view_name } = $view;
    }

    return $view;
}

# ----------------------------------------------------------------------
sub database {

=pod

=head2 database

Get or set the schema's database.  (optional)

  my $database = $schema->database('PostgreSQL');

=cut

    my $self = shift;
    $self->{'database'} = shift if @_;
    return $self->{'database'} || '';
}

# ----------------------------------------------------------------------
sub is_valid {

=pod

=head2 is_valid

Returns true if all the tables and views are valid.

  my $ok = $schema->is_valid or die $schema->error;

=cut

    my $self = shift;

    return $self->error('No tables') unless $self->get_tables;

    for my $object ( $self->get_tables, $self->get_views ) {
        return $object->error unless $object->is_valid;
    }

    return 1;
}

# ----------------------------------------------------------------------
sub get_table {

=pod

=head2 get_table

Returns a table by the name provided.

  my $table = $schema->get_table('foo');

=cut

    my $self       = shift;
    my $table_name = shift or return $self->error('No table name');
    return $self->error( qq[Table "$table_name" does not exist] ) unless
        exists $self->{'tables'}{ $table_name };
    return $self->{'tables'}{ $table_name };
}

# ----------------------------------------------------------------------
sub get_tables {

=pod

=head2 get_tables

Returns all the tables as an array or array reference.

  my @tables = $schema->get_tables;

=cut

    my $self   = shift;
    my @tables = 
        map  { $_->[1] } 
        sort { $a->[0] <=> $b->[0] } 
        map  { [ $_->order, $_ ] }
        values %{ $self->{'tables'} };

    if ( @tables ) {
        return wantarray ? @tables : \@tables;
    }
    else {
        $self->error('No tables');
        return wantarray ? () : undef;
    }
}

# ----------------------------------------------------------------------
sub get_view {

=pod

=head2 get_view

Returns a view by the name provided.

  my $view = $schema->get_view('foo');

=cut

    my $self      = shift;
    my $view_name = shift or return $self->error('No view name');
    return $self->error('View "$view_name" does not exist') unless
        exists $self->{'views'}{ $view_name };
    return $self->{'views'}{ $view_name };
}

# ----------------------------------------------------------------------
sub get_views {

=pod

=head2 get_views

Returns all the views as an array or array reference.

  my @views = $schema->get_views;

=cut

    my $self  = shift;
    my @views = 
        map  { $_->[1] } 
        sort { $a->[0] <=> $b->[0] } 
        map  { [ $_->order, $_ ] }
        values %{ $self->{'views'} };

    if ( @views ) {
        return wantarray ? @views : \@views;
    }
    else {
        $self->error('No views');
        return wantarray ? () : undef;
    }
}

# ----------------------------------------------------------------------
sub make_natural_joins {

=pod

=head2 make_natural_joins

Creates foriegn key relationships among like-named fields in different
tables.  Accepts the following arguments:

=over 4

=item * join_pk_only 

A True or False argument which determins whether or not to perform 
the joins from primary keys to fields of the same name in other tables

=item * skip_fields

A list of fields to skip in the joins

=back 4

  $schema->make_natural_joins(
      join_pk_only => 1,
      skip_fields  => 'name,department_id',
  );

=cut

    my $self         = shift;
    my %args         = @_;
    my $join_pk_only = $args{'join_pk_only'} || 0;
    my %skip_fields  = map { $_, 1 } @{ parse_list_arg($args{'skip_fields'}) };

    my ( %common_keys, %pk );
    for my $table ( $self->get_tables ) {
        for my $field ( $table->get_fields ) {
            my $field_name = $field->name or next;
            next if $skip_fields{ $field_name };
            $pk{ $field_name } = 1 if $field->is_primary_key;
            push @{ $common_keys{ $field_name } }, $table->name;
        }
    } 
   
    for my $field ( keys %common_keys ) {
        next if $join_pk_only and !defined $pk{ $field };

        my @table_names = @{ $common_keys{ $field } };
        next unless scalar @table_names > 1;

        for my $i ( 0 .. $#table_names ) {
            my $table1 = $self->get_table( $table_names[ $i ] ) or next;

            for my $j ( 1 .. $#table_names ) {
                my $table2 = $self->get_table( $table_names[ $j ] ) or next;
                next if $table1->name eq $table2->name;

                $table1->add_constraint(
                    type             => FOREIGN_KEY,
                    fields           => $field,
                    reference_table  => $table2->name,
                    reference_fields => $field,
                );
            }               
        }
    } 

    return 1;
}

# ----------------------------------------------------------------------
sub name {

=pod

=head2 name

Get or set the schema's name.  (optional)

  my $schema_name = $schema->name('Foo Database');

=cut

    my $self = shift;
    $self->{'name'} = shift if @_;
    return $self->{'name'} || '';
}

# ----------------------------------------------------------------------
sub DESTROY {
    my $self = shift;
    undef $_ for values %{ $self->{'tables'} };
    undef $_ for values %{ $self->{'views'}  };
}

1;

# ----------------------------------------------------------------------

=pod

=head1 AUTHOR

Ken Y. Clark E<lt>kclark@cpan.orgE<gt>

=cut
Commit	Line	Data
3c5de62a	1	package SQL::Translator::Schema;
	2
	3	# ----------------------------------------------------------------------
9480e70b	4	# $Id: Schema.pm,v 1.6 2003-06-09 04:18:23 kycl4rk Exp $
3c5de62a	5	# ----------------------------------------------------------------------
	6	# Copyright (C) 2003 Ken Y. Clark <kclark@cpan.org>
	7	#
	8	# This program is free software; you can redistribute it and/or
	9	# modify it under the terms of the GNU General Public License as
	10	# published by the Free Software Foundation; version 2.
	11	#
	12	# This program is distributed in the hope that it will be useful, but
	13	# WITHOUT ANY WARRANTY; without even the implied warranty of
	14	# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	# General Public License for more details.
	16	#
	17	# You should have received a copy of the GNU General Public License
	18	# along with this program; if not, write to the Free Software
	19	# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	20	# 02111-1307 USA
	21	# -------------------------------------------------------------------
	22
	23	=pod
	24
	25	=head1 NAME
	26
	27	SQL::Translator::Schema - SQL::Translator schema object
	28
	29	=head1 SYNOPSIS
	30
	31	use SQL::Translator::Schema;
76dce619	32	my $schema = SQL::Translator::Schema->new;
	33	my $table = $schema->add_table( name => 'foo' );
	34	my $view = $schema->add_view( name => 'bar', sql => '...' );
3c5de62a	35
	36	=head1 DESCSIPTION
	37
	38	C<SQL::Translator::Schema> is the object that accepts, validates, and
	39	returns the database structure.
	40
	41	=head1 METHODS
	42
	43	=cut
	44
	45	use strict;
	46	use Class::Base;
9480e70b	47	use SQL::Translator::Schema::Constants;
3c5de62a	48	use SQL::Translator::Schema::Table;
	49	use SQL::Translator::Schema::View;
	50
	51	use base 'Class::Base';
76dce619	52	use vars qw[ $VERSION $TABLE_ORDER $VIEW_ORDER ];
3c5de62a	53
	54	$VERSION = 1.00;
	55
	56	# ----------------------------------------------------------------------
	57	sub init {
	58
	59	=pod
	60
	61	=head2 new
	62
	63	Object constructor.
	64
99248301	65	my $schema = SQL::Translator->new(
	66	name => 'Foo',
	67	database => 'MySQL',
	68	);
3c5de62a	69
	70	=cut
	71
	72	my ( $self, $config ) = @_;
99248301	73	$self->params( $config, qw[ name database ] ) \|\| return undef;
3c5de62a	74	return $self;
	75	}
	76
	77	# ----------------------------------------------------------------------
76dce619	78	sub add_table {
3c5de62a	79
	80	=pod
	81
76dce619	82	=head2 add_table
3c5de62a	83
76dce619	84	Add a table object. Returns the new SQL::Translator::Schema::Table object.
99248301	85	The "name" parameter is required. If you try to create a table with the
	86	same name as an existing table, you will get an error and the table will
	87	not be created.
3c5de62a	88
68e8e2e1	89	my $t1 = $schema->add_table( name => 'foo' ) or die $schema->error;
	90	my $t2 = SQL::Translator::Schema::Table->new( name => 'bar' );
	91	$t2 = $schema->add_table( $table_bar ) or die $schema->error;
3c5de62a	92
	93	=cut
	94
99248301	95	my $self = shift;
	96	my $table_class = 'SQL::Translator::Schema::Table';
	97	my $table;
	98
	99	if ( UNIVERSAL::isa( $_[0], $table_class ) ) {
	100	$table = shift;
	101	$table->schema( $self );
	102	}
	103	else {
	104	my %args = @_;
	105	$args{'schema'} = $self;
	106	$table = $table_class->new( \%args ) or return
	107	$self->error( $table_class->error );
	108	}
3c5de62a	109
d0b43695	110	$table->order( ++$TABLE_ORDER );
99248301	111	my $table_name = $table->name or return $self->error('No table name');
	112
	113	if ( defined $self->{'tables'}{ $table_name } ) {
	114	return $self->error(qq[Can't create table: "$table_name" exists]);
	115	}
	116	else {
	117	$self->{'tables'}{ $table_name } = $table;
99248301	118	}
3c5de62a	119
	120	return $table;
	121	}
	122
	123	# ----------------------------------------------------------------------
76dce619	124	sub add_view {
3c5de62a	125
	126	=pod
	127
76dce619	128	=head2 add_view
3c5de62a	129
76dce619	130	Add a view object. Returns the new SQL::Translator::Schema::View object.
99248301	131	The "name" parameter is required. If you try to create a view with the
	132	same name as an existing view, you will get an error and the view will
	133	not be created.
	134
68e8e2e1	135	my $v1 = $schema->add_view( name => 'foo' );
	136	my $v2 = SQL::Translator::Schema::View->new( name => 'bar' );
	137	$v2 = $schema->add_view( $view_bar ) or die $schema->error;
3c5de62a	138
	139	=cut
	140
99248301	141	my $self = shift;
	142	my $view_class = 'SQL::Translator::Schema::View';
	143	my $view;
	144
	145	if ( UNIVERSAL::isa( $_[0], $view_class ) ) {
	146	$view = shift;
	147	}
	148	else {
	149	my %args = @_;
	150	return $self->error('No view name') unless $args{'name'};
	151	$view = $view_class->new( \%args ) or return $view_class->error;
	152	}
3c5de62a	153
d0b43695	154	$view->order( ++$VIEW_ORDER );
99248301	155	my $view_name = $view->name or return $self->error('No view name');
	156
	157	if ( defined $self->{'views'}{ $view_name } ) {
	158	return $self->error(qq[Can't create view: "$view_name" exists]);
	159	}
	160	else {
	161	$self->{'views'}{ $view_name } = $view;
99248301	162	}
3c5de62a	163
76dce619	164	return $view;
3c5de62a	165	}
	166
	167	# ----------------------------------------------------------------------
99248301	168	sub database {
	169
	170	=pod
	171
	172	=head2 database
	173
	174	Get or set the schema's database. (optional)
	175
	176	my $database = $schema->database('PostgreSQL');
	177
	178	=cut
	179
	180	my $self = shift;
	181	$self->{'database'} = shift if @_;
	182	return $self->{'database'} \|\| '';
	183	}
	184
	185	# ----------------------------------------------------------------------
76dce619	186	sub is_valid {
3c5de62a	187
	188	=pod
	189
76dce619	190	=head2 is_valid
3c5de62a	191
76dce619	192	Returns true if all the tables and views are valid.
3c5de62a	193
76dce619	194	my $ok = $schema->is_valid or die $schema->error;
	195
	196	=cut
	197
	198	my $self = shift;
	199
	200	return $self->error('No tables') unless $self->get_tables;
	201
	202	for my $object ( $self->get_tables, $self->get_views ) {
	203	return $object->error unless $object->is_valid;
	204	}
	205
	206	return 1;
	207	}
	208
	209	# ----------------------------------------------------------------------
	210	sub get_table {
	211
	212	=pod
	213
	214	=head2 get_table
	215
	216	Returns a table by the name provided.
	217
	218	my $table = $schema->get_table('foo');
	219
	220	=cut
	221
	222	my $self = shift;
	223	my $table_name = shift or return $self->error('No table name');
99248301	224	return $self->error( qq[Table "$table_name" does not exist] ) unless
76dce619	225	exists $self->{'tables'}{ $table_name };
	226	return $self->{'tables'}{ $table_name };
	227	}
	228
	229	# ----------------------------------------------------------------------
	230	sub get_tables {
	231
	232	=pod
	233
	234	=head2 get_tables
	235
	236	Returns all the tables as an array or array reference.
	237
	238	my @tables = $schema->get_tables;
	239
	240	=cut
	241
	242	my $self = shift;
d0b43695	243	my @tables =
	244	map { $_->[1] }
	245	sort { $a->[0] <=> $b->[0] }
	246	map { [ $_->order, $_ ] }
76dce619	247	values %{ $self->{'tables'} };
	248
	249	if ( @tables ) {
	250	return wantarray ? @tables : \@tables;
	251	}
	252	else {
	253	$self->error('No tables');
	254	return wantarray ? () : undef;
	255	}
	256	}
	257
	258	# ----------------------------------------------------------------------
	259	sub get_view {
	260
	261	=pod
	262
	263	=head2 get_view
	264
	265	Returns a view by the name provided.
	266
	267	my $view = $schema->get_view('foo');
3c5de62a	268
	269	=cut
	270
	271	my $self = shift;
76dce619	272	my $view_name = shift or return $self->error('No view name');
	273	return $self->error('View "$view_name" does not exist') unless
	274	exists $self->{'views'}{ $view_name };
	275	return $self->{'views'}{ $view_name };
	276	}
3c5de62a	277
76dce619	278	# ----------------------------------------------------------------------
76dce619	279	sub get_views {
3c5de62a	280
76dce619	281	=pod
	282
	283	=head2 get_views
	284
	285	Returns all the views as an array or array reference.
	286
	287	my @views = $schema->get_views;
	288
	289	=cut
	290
	291	my $self = shift;
d0b43695	292	my @views =
	293	map { $_->[1] }
	294	sort { $a->[0] <=> $b->[0] }
	295	map { [ $_->order, $_ ] }
99248301	296	values %{ $self->{'views'} };
76dce619	297
	298	if ( @views ) {
	299	return wantarray ? @views : \@views;
	300	}
	301	else {
	302	$self->error('No views');
	303	return wantarray ? () : undef;
	304	}
3c5de62a	305	}
3c5de62a	306
99248301	307	# ----------------------------------------------------------------------
9480e70b	308	sub make_natural_joins {
	309
	310	=pod
	311
	312	=head2 make_natural_joins
	313
	314	Creates foriegn key relationships among like-named fields in different
	315	tables. Accepts the following arguments:
	316
	317	=over 4
	318
	319	=item * join_pk_only
	320
	321	A True or False argument which determins whether or not to perform
	322	the joins from primary keys to fields of the same name in other tables
	323
	324	=item * skip_fields
	325
	326	A list of fields to skip in the joins
	327
	328	=back 4
	329
	330	$schema->make_natural_joins(
	331	join_pk_only => 1,
	332	skip_fields => 'name,department_id',
	333	);
	334
	335	=cut
	336
	337	my $self = shift;
	338	my %args = @_;
	339	my $join_pk_only = $args{'join_pk_only'} \|\| 0;
	340	my %skip_fields = map { $_, 1 } @{ parse_list_arg($args{'skip_fields'}) };
	341
	342	my ( %common_keys, %pk );
	343	for my $table ( $self->get_tables ) {
	344	for my $field ( $table->get_fields ) {
	345	my $field_name = $field->name or next;
	346	next if $skip_fields{ $field_name };
	347	$pk{ $field_name } = 1 if $field->is_primary_key;
	348	push @{ $common_keys{ $field_name } }, $table->name;
	349	}
	350	}
	351
	352	for my $field ( keys %common_keys ) {
	353	next if $join_pk_only and !defined $pk{ $field };
	354
	355	my @table_names = @{ $common_keys{ $field } };
	356	next unless scalar @table_names > 1;
	357
	358	for my $i ( 0 .. $#table_names ) {
	359	my $table1 = $self->get_table( $table_names[ $i ] ) or next;
	360
	361	for my $j ( 1 .. $#table_names ) {
	362	my $table2 = $self->get_table( $table_names[ $j ] ) or next;
	363	next if $table1->name eq $table2->name;
	364
	365	$table1->add_constraint(
	366	type => FOREIGN_KEY,
	367	fields => $field,
	368	reference_table => $table2->name,
	369	reference_fields => $field,
	370	);
	371	}
372	}
373	}
374
375	return 1;
376	}
377
378	# ----------------------------------------------------------------------
99248301	379	sub name {
	380
	381	=pod
	382
	383	=head2 name
	384
	385	Get or set the schema's name. (optional)
	386
	387	my $schema_name = $schema->name('Foo Database');
	388
	389	=cut
	390
	391	my $self = shift;
	392	$self->{'name'} = shift if @_;
	393	return $self->{'name'} \|\| '';
	394	}
	395
d0b43695	396	# ----------------------------------------------------------------------
	397	sub DESTROY {
	398	my $self = shift;
	399	undef $_ for values %{ $self->{'tables'} };
	400	undef $_ for values %{ $self->{'views'} };
	401	}
	402
3c5de62a	403	1;
	404
	405	# ----------------------------------------------------------------------
	406
	407	=pod
	408
	409	=head1 AUTHOR
	410
	411	Ken Y. Clark E<lt>kclark@cpan.orgE<gt>
	412
	413	=cut