1 package SQL::Translator::Producer::ClassDBI;
3 # -------------------------------------------------------------------
4 # $Id: ClassDBI.pm,v 1.31 2003-08-13 17:13:53 kycl4rk Exp $
5 # -------------------------------------------------------------------
6 # Copyright (C) 2003 Allen Day <allenday@ucla.edu>,
7 # Ying Zhang <zyolive@yahoo.com>
9 # This program is free software; you can redistribute it and/or
10 # modify it under the terms of the GNU General Public License as
11 # published by the Free Software Foundation; version 2.
13 # This program is distributed in the hope that it will be useful, but
14 # WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 # General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
22 # -------------------------------------------------------------------
25 use vars qw[ $VERSION $DEBUG ];
26 $VERSION = sprintf "%d.%02d", q$Revision: 1.31 $ =~ /(\d+)\.(\d+)/;
27 $DEBUG = 1 unless defined $DEBUG;
29 use SQL::Translator::Schema::Constants;
30 use SQL::Translator::Utils qw(header_comment);
33 my %CDBI_auto_pkgs = (
39 # -------------------------------------------------------------------
43 local $DEBUG = $t->debug;
44 my $no_comments = $t->no_comments;
45 my $schema = $t->schema;
46 my $args = $t->producer_args;
47 my $db_user = $args->{'db_user'} || '';
48 my $db_pass = $args->{'db_pass'} || '';
49 my $main_pkg_name = $args->{'main_pkg_name'} ||
50 $t->format_package_name('DBI');
51 my $header = header_comment( __PACKAGE__, "# " );
52 my $parser_type = ( split /::/, $t->parser_type )[-1];
53 my $from = $CDBI_auto_pkgs{$parser_type} || '';
54 my $dsn = $args->{'dsn'} || sprintf( 'dbi:%s:_',
55 $CDBI_auto_pkgs{$parser_type}
56 ? $CDBI_auto_pkgs{$parser_type}
58 my $sep = '# ' . '-' x 67;
61 # Identify "link tables" (have only PK and FK fields).
65 foreach my $table ( $schema->get_tables ) {
67 foreach my $field ( $table->get_fields ) {
68 unless ( $field->is_primary_key or $field->is_foreign_key ) {
76 foreach my $left ( $table->get_fields ) {
77 next unless $left->is_foreign_key;
78 my $lfk = $left->foreign_key_reference or next;
79 my $lr_table = $schema->get_table( $lfk->reference_table )
81 my $lr_field_name = ( $lfk->reference_fields )[0];
82 my $lr_field = $lr_table->get_field($lr_field_name);
83 next unless $lr_field->is_primary_key;
85 foreach my $right ( $table->get_fields ) {
86 next if $left->name eq $right->name;
88 my $rfk = $right->foreign_key_reference or next;
89 my $rr_table = $schema->get_table( $rfk->reference_table )
91 my $rr_field_name = ( $rfk->reference_fields )[0];
92 my $rr_field = $rr_table->get_field($rr_field_name);
93 next unless $rr_field->is_primary_key;
95 $linkable{ $lr_table->name }{ $rr_table->name } = $table;
96 $linkable{ $rr_table->name }{ $lr_table->name } = $table;
97 $linktable{ $table->name } = $table;
103 # Iterate over all tables.
105 my ( %packages, $order );
106 for my $table ( $schema->get_tables ) {
107 my $table_name = $table->name or next;
109 my $table_pkg_name = $t->format_package_name($table_name);
110 $packages{$table_pkg_name} = {
112 pkg_name => $table_pkg_name,
113 base => $main_pkg_name,
114 table => $table_name,
118 # Primary key may have a differenct accessor method name
120 if ( my $constraint = $table->primary_key ) {
121 my $field = ( $constraint->fields )[0];
122 $packages{ $table_pkg_name }{'_columns_primary'} = $field;
124 if ( my $pk_xform = $t->format_pk_name ) {
125 my $pk_name = $pk_xform->( $table_pkg_name, $field );
127 $packages{$table_pkg_name}{'pk_accessor'} =
128 "#\n# Primary key accessor\n#\n"
129 . "sub $pk_name {\n shift->$field\n}\n\n";
134 foreach my $field ( $table->get_fields ) {
135 if ( !$field->is_foreign_key and !$field->is_primary_key ) {
136 push @{ $packages{$table_pkg_name}{'_columns_essential'} },
140 elsif ( !$field->is_primary_key ) {
141 push @{ $packages{$table_pkg_name}{'_columns_others'} },
148 foreach my $link ( keys %{ $linkable{$table_name} } ) {
151 if ( my $fk_xform = $t->format_fk_name ) {
152 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
153 $linkmethodname = $fk_xform->(
154 $linkable{$table_name}{$link}->name,
155 ( $schema->get_table($link)->primary_key->fields )[0]
161 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
163 $linkable{$table_name}{$link}->name . '_'
164 . ( $schema->get_table($link)->primary_key->fields )[0]
170 foreach my $field ( $linkable{$table_name}{$link}->get_fields )
172 next unless $field->is_foreign_key;
175 unless ( $field->foreign_key_reference->reference_table eq
177 || $field->foreign_key_reference->reference_table eq
180 ( $field->foreign_key_reference->reference_fields )[0]
181 if $field->foreign_key_reference->reference_table eq
183 push @rk_fields, $field->name
184 if $field->foreign_key_reference->reference_table eq
189 # If one possible traversal via link table.
191 if ( scalar(@rk_fields) == 1 and scalar(@lk_fields) == 1 ) {
192 foreach my $rk_field (@rk_fields) {
193 push @{ $packages{$table_pkg_name}{'has_many'}{$link} },
196 . " { my \$self = shift; "
198 . ( $schema->get_table($link)->primary_key->fields )
201 . $linkable{$table_name}{$link}->name . "_"
207 # Else there is more than one way to traverse it.
208 # ack! Let's treat these types of link tables as
209 # a many-to-one (easier).
211 # NOTE: We need to rethink the link method name,
212 # as the cardinality has shifted on us.
215 elsif ( scalar(@rk_fields) == 1 ) {
216 foreach my $rk_field (@rk_fields) {
218 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
219 push @{ $packages{$table_pkg_name}{'has_many'}{$link} },
221 . $linkable{$table_name}{$link}->name
222 . "s { my \$self = shift; return \$self->"
223 . $linkable{$table_name}{$link}->name . "_"
228 elsif ( scalar(@lk_fields) == 1 ) {
229 # These will be taken care of on the other end...
233 # Many many many. Need multiple iterations here,
234 # data structure revision to handle N FK sources.
235 # This code has not been tested and likely doesn't
238 foreach my $rk_field (@rk_fields) {
240 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
241 push @{ $packages{$table_pkg_name}{'has_many'}{$link} },
243 . $linkable{$table_name}{$link}->name . "_"
245 . "s { my \$self = shift; return \$self->"
246 . $linkable{$table_name}{$link}->name . "_"
255 # Use foreign keys to set up "has_a/has_many" relationships.
257 foreach my $field ( $table->get_fields ) {
258 if ( $field->is_foreign_key ) {
259 my $table_name = $table->name;
260 my $field_name = $field->name;
261 my $fk_method = $t->format_fk_name( $table_name, $field_name )
263 my $fk = $field->foreign_key_reference;
264 my $ref_table = $fk->reference_table;
265 my $ref_pkg = $t->format_package_name($ref_table);
266 my $ref_field = ( $fk->reference_fields )[0];
268 push @{ $packages{$table_pkg_name}{'has_a'} },
269 "$table_pkg_name->has_a(\n"
270 . " $field_name => '$ref_pkg'\n);\n\n"
271 . "sub $fk_method {\n"
272 . " return shift->$field_name\n}\n\n"
276 # If this table "has a" to the other, then it follows
277 # that the other table "has many" of this one, right?
279 # No... there is the possibility of 1-1 cardinality
281 # If there weren't M-M relationships via the has_many
282 # being set up here, create nice pluralized method alias
283 # rather for user as alt. to ugly tablename_fieldname name.
285 if ( !$packages{$ref_pkg}{'has_many'}{$table_name} ) {
287 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
288 push @{ $packages{$ref_pkg}{'has_many'}{$table_name} },
289 "sub ${table_name}s {\n ".
290 "return shift->$table_name\_$field_name\n}\n\n"
294 ; # nothing? why is this here? -ky
297 push @{ $packages{$ref_pkg}{'has_many'}{$table_name} },
298 "$ref_pkg->has_many(\n '${table_name}_${field_name}',\n"
299 . " '$table_pkg_name' => '$field_name'\n);\n\n"
306 # Now build up text of package.
308 my $base_pkg = sprintf( 'Class::DBI%s', $from ? "::$from" : '' );
309 $create .= join ( "\n",
310 "package $main_pkg_name;\n",
313 "use base '$base_pkg';\n",
314 "$main_pkg_name->set_db('Main', '$dsn', '$db_user', '$db_pass');\n\n",
318 sort { $packages{ $a }{'order'} <=> $packages{ $b }{'order'} }
321 my $pkg = $packages{ $pkg_name };
323 $create .= join ( "\n",
325 "package " . $pkg->{'pkg_name'} . ";",
326 "use base '" . $pkg->{'base'} . "';",
327 "use Class::DBI::Pager;\n\n",
331 # The approach here is to do lazy loading on the expensive
332 # columns (expensive defined as those columns which require
333 # construction of a referenced object) fields which are
334 # strictly data (ie, not references) are treated as essential
335 # b/c they don't require much time to set up.
337 $create .= $pkg_name . "->table('" . $pkg->{'table'} . "');\n\n";
339 # set up primary key field
340 if ( $pkg->{'_columns_primary'} ) {
342 . "->columns(\n Primary => qw/"
343 . $pkg->{'_columns_primary'} . "/\n);\n\n";
346 die "Class::DBI isn't going to like that you don't have".
347 " a primary key field for table " . $pkg->{'table'} .
348 " in package '$pkg_name'";
352 # Set up non-FK fields to be populated at construction.
354 if ( $pkg->{'_columns_essential'} ) {
357 . autoformat( ' Essential => qw/' .
358 join ( ' ', @{ $pkg->{'_columns_essential'} } ) . '/'
364 # Set up FK fields for lazy loading on request.
366 if ( $pkg->{'_columns_others'} ) {
369 . autoformat( ' Others => qw/' .
370 join ( ' ', @{ $pkg->{'_columns_others'} } ) . '/'
375 if ( my $pk = $pkg->{'pk_accessor'} ) {
379 if ( my @has_a = @{ $pkg->{'has_a'} || [] } ) {
380 $create .= $_ for @has_a;
383 foreach my $has_many_key ( keys %{ $pkg->{'has_many'} } ) {
384 if ( my @has_many = @{ $pkg->{'has_many'}{$has_many_key} || [] } ) {
385 $create .= $_ for @has_many;
397 # -------------------------------------------------------------------
403 SQL::Translator::Producer::ClassDBI - create Class::DBI classes from schema
407 Use this producer as you would any other from SQL::Translator. See
408 L<SQL::Translator> for details.
410 This package utilizes SQL::Translator's formatting methods
411 format_package_name(), format_pk_name(), format_fk_name(), and
412 format_table_name() as it creates classes, one per table in the schema
413 provided. An additional base class is also created for database connectivity
414 configuration. See L<Class::DBI> for details on how this works.
418 Allen Day E<lt>allenday@ucla.eduE<gt>
419 Ying Zhang E<lt>zyolive@yahoo.comE<gt>,
420 Ken Y. Clark E<lt>kclark@cpan.org<gt>.