lib/SQL/Translator/Producer/ClassDBI.pm

   1 package SQL::Translator::Producer::ClassDBI;
   2
   3 # -------------------------------------------------------------------
   4 # $Id: ClassDBI.pm,v 1.29 2003-08-07 03:51:48 allenday Exp $
   5 # -------------------------------------------------------------------
   6 # Copyright (C) 2003 Allen Day <allenday@ucla.edu>,
   7 #                    Ying Zhang <zyolive@yahoo.com>
   8 #
   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.
  12 #
  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.
  17 #
  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
  21 # 02111-1307  USA
  22 # -------------------------------------------------------------------
  23
  24 use strict;
  25 use vars qw[ $VERSION $DEBUG ];
  26 $VERSION = sprintf "%d.%02d", q$Revision: 1.29 $ =~ /(\d+)\.(\d+)/;
  27 $DEBUG   = 1 unless defined $DEBUG;
  28
  29 use SQL::Translator::Schema::Constants;
  30 use SQL::Translator::Utils qw(header_comment);
  31 use Data::Dumper;
  32
  33 my %CDBI_auto_pkgs = (
  34     MySQL      => 'mysql',
  35     PostgreSQL => 'Pg',
  36     Oracle     => 'Oracle',
  37 );
  38
  39 # -------------------------------------------------------------------
  40 sub produce {
  41     my $t             = shift;
  42         my $create        = undef;
  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 = $t->format_package_name('DBI');
  50     my $header        = header_comment(__PACKAGE__, "# ");
  51     my $parser_type   = ( split /::/, $t->parser_type )[-1];
  52     my $from          = $CDBI_auto_pkgs{ $parser_type } || '';
  53     my $dsn           = $args->{'dsn'} || sprintf( 'dbi:%s:_',
  54                             $CDBI_auto_pkgs{ $parser_type }
  55                             ? $CDBI_auto_pkgs{ $parser_type } : $parser_type
  56                         );
  57     my $sep           = '# ' . '-' x 67;
  58
  59     #
  60     # Identify "link tables" (have only PK and FK fields).
  61     #
  62     my %linkable;
  63     my %linktable;
  64     foreach my $table ( $schema->get_tables ) {
  65         my $is_link = 1;
  66         foreach my $field ( $table->get_fields ) {
  67             unless ( $field->is_primary_key or $field->is_foreign_key ) {
  68                 $is_link = 0;
  69                 last;
  70             }
  71         }
  72
  73         next unless $is_link;
  74
  75         foreach my $left ( $table->get_fields ) {
  76             next unless $left->is_foreign_key;
  77             my $lfk           = $left->foreign_key_reference or next;
  78             my $lr_table      = $schema->get_table( $lfk->reference_table )
  79                                  or next;
  80             my $lr_field_name = ($lfk->reference_fields)[0];
  81             my $lr_field      = $lr_table->get_field($lr_field_name);
  82             next unless $lr_field->is_primary_key;
  83
  84             foreach my $right ( $table->get_fields ) {
  85                 next if $left->name eq $right->name;
  86
  87                 my $rfk      = $right->foreign_key_reference or next;
  88                 my $rr_table = $schema->get_table( $rfk->reference_table )
  89                                or next;
  90                 my $rr_field_name = ($rfk->reference_fields)[0];
  91                 my $rr_field      = $rr_table->get_field($rr_field_name);
  92                 next unless $rr_field->is_primary_key;
  93
  94                 $linkable{ $lr_table->name }{ $rr_table->name } = $table;
  95                 $linkable{ $rr_table->name }{ $lr_table->name } = $table;
  96                 $linktable{ $table->name } = $table;
  97             }
  98         }
  99     }
 100
 101     #
 102     # Iterate over all tables
 103     #
 104     my ( %packages, $order );
 105     for my $table ( $schema->get_tables ) {
 106         my $table_name = $table->name or next;
 107
 108         my $table_pkg_name = $t->format_package_name($table_name);
 109         $packages{ $table_pkg_name } = {
 110             order     => ++$order,
 111             pkg_name  => $table_pkg_name,
 112             base      => $main_pkg_name,
 113             table     => $table_name,
 114         };
 115
 116         #
 117         # Primary key may have a differenct accessor method name
 118         #
 119         if ( my $pk_xform = $t->format_pk_name ) {
 120             if ( my $constraint = $table->primary_key ) {
 121                 my $field          = ($constraint->fields)[0];
 122                 my $pk_name        = $pk_xform->($table_pkg_name, $field);
 123
 124                                 $packages{ $table_pkg_name }{'_columns_primary'} = $field;
 125
 126                 $packages{ $table_pkg_name }{'pk_accessor'} =
 127                     "#\n# Primary key accessor\n#\n".
 128                     "sub $pk_name {\n    shift->$field\n}\n\n"
 129                 ;
 130             }
 131         }
 132
 133         my $is_data = 0;
 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'} }, $field->name;
 137                         $is_data++;
 138                   } elsif ( !$field->is_primary_key ) {
 139                         push @{ $packages{ $table_pkg_name }{'_columns_others'} }, $field->name;
 140                   }
 141                 }
 142
 143                 my %linked;
 144                 if ( $is_data ) {
 145                   foreach my $link ( keys %{ $linkable{ $table_name } } ) {
 146                         my $linkmethodname;
 147
 148                         if ( my $fk_xform = $t->format_fk_name ) {
 149                           # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 150                           $linkmethodname = $fk_xform->($linkable{$table_name}{$link}->name,
 151                                                                                         ($schema->get_table($link)->primary_key->fields)[0]).'s';
 152                         } else {
 153                           # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 154                           $linkmethodname = $linkable{$table_name}{$link}->name.'_'.
 155                                 ($schema->get_table($link)->primary_key->fields)[0].'s';
 156                         }
 157
 158                         my @rk_fields = ();
 159                         my @lk_fields = ();
 160                         foreach my $field ($linkable{$table_name}{$link}->get_fields) {
 161                           next unless $field->is_foreign_key;
 162
 163                           next unless(
 164                                                   $field->foreign_key_reference->reference_table eq $table_name
 165                                                   ||
 166                                                   $field->foreign_key_reference->reference_table eq $link
 167                                                  );
 168                           push @lk_fields, ($field->foreign_key_reference->reference_fields)[0]
 169                                 if $field->foreign_key_reference->reference_table eq $link;
 170                           push @rk_fields, $field->name
 171                                 if $field->foreign_key_reference->reference_table eq $table_name;
 172                         }
 173
 174                         #if one possible traversal via link table
 175                         if (scalar(@rk_fields) == 1 and scalar(@lk_fields) == 1) {
 176                           foreach my $rk_field (@rk_fields) {
 177                                 push @{ $packages{ $table_pkg_name }{'has_many'}{ $link } },
 178                                   "sub ".$linkmethodname." { my \$self = shift; ".
 179                                         "return map \$_->".
 180                                           ($schema->get_table($link)->primary_key->fields)[0].
 181                                                 ", \$self->".$linkable{$table_name}{$link}->name.
 182                                                   "_".$rk_field." }\n\n";
 183                           }
 184                           #else there is more than one way to traverse it.  ack!
 185                           #let's treat these types of link tables as a many-to-one (easier)
 186                           #
 187                           #NOTE: we need to rethink the link method name, as the cardinality
 188                           #has shifted on us.
 189                         } elsif (scalar(@rk_fields) == 1) {
 190                           foreach my $rk_field (@rk_fields) {
 191                                 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 192                                 push @{ $packages{ $table_pkg_name }{'has_many'}{ $link } },
 193                                   "sub " . $linkable{$table_name}{$link}->name .
 194                                         "s { my \$self = shift; return \$self->" .
 195                                           $linkable{$table_name}{$link}->name . "_" .
 196                                                 $rk_field . "(\@_) }\n\n";
 197                           }
 198                         } elsif (scalar(@lk_fields) == 1) {
 199                           #these will be taken care of on the other end...
 200                         } else {
 201                           #many many many.  need multiple iterations here, data structure revision
 202                           #to handle N FK sources.  This code has not been tested and likely doesn't
 203                           #work here
 204                           foreach my $rk_field (@rk_fields) {
 205                                 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 206                                 push @{ $packages{ $table_pkg_name }{'has_many'}{ $link } },
 207                                   "sub " . $linkable{$table_name}{$link}->name . "_" . $rk_field .
 208                                         "s { my \$self = shift; return \$self->" .
 209                                           $linkable{$table_name}{$link}->name . "_" .
 210                                                 $rk_field . "(\@_) }\n\n";
 211                           }
 212                         }
 213                   }
 214         }
 215
 216
 217         #
 218         # Use foreign keys to set up "has_a/has_many" relationships.
 219         #
 220         foreach my $field ( $table->get_fields ) {
 221             if ( $field->is_foreign_key ) {
 222                 my $table_name = $table->name;
 223                 my $field_name = $field->name;
 224                 my $fk_method  = $t->format_fk_name($table_name, $field_name);
 225                 my $fk         = $field->foreign_key_reference;
 226                 my $ref_table  = $fk->reference_table;
 227                 my $ref_pkg    = $t->format_package_name($ref_table);
 228                 my $ref_field  = ($fk->reference_fields)[0];
 229
 230                 push @{ $packages{ $table_pkg_name }{'has_a'} },
 231                     "$table_pkg_name->has_a(\n".
 232                     "    $field_name => '$ref_pkg'\n);\n\n".
 233                     "sub $fk_method {\n".
 234                     "    return shift->$field_name\n}\n\n"
 235                 ;
 236
 237                 #
 238                 # If this table "has a" to the other, then it follows
 239                 # that the other table "has many" of this one, right?
 240                 #
 241                                 # No... there is the possibility of 1-1 cardinality
 242
 243                                 #if there weren't M-M relationships via the has_many
 244                                 #being set up here, create nice pluralized method alias
 245                                 #rather for user as alt. to ugly tablename_fieldname name
 246                                 if(! $packages{ $ref_pkg }{ 'has_many' }{ $table_name } ){
 247                                   # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 248                                   push @{ $packages{ $ref_pkg }{'has_many'}{ $table_name } },
 249                                         "sub $table_name\s {\n    return shift->$table_name\_$field_name\n}\n\n";
 250
 251                                 #else ugly
 252                                 } else {
 253                                 }
 254
 255                                 push @{ $packages{ $ref_pkg }{'has_many'}{ $table_name } },
 256                                   "$ref_pkg->has_many(\n    '${table_name}_${field_name}', ".
 257                                   "'$table_pkg_name' => '$field_name'\n);\n\n";
 258
 259             }
 260                 }
 261         }
 262
 263     #
 264     # Now build up text of package.
 265     #
 266     my $base_pkg = sprintf( 'Class::DBI%s', $from ? "::$from" : '' );
 267     $create .= join("\n",
 268       "package $main_pkg_name;\n",
 269       $header,
 270       "use strict;",
 271       "use base '$base_pkg';\n",
 272       "$main_pkg_name->set_db('Main', '$dsn', '$db_user', '$db_pass');\n\n",
 273     );
 274
 275     for my $pkg_name (
 276         sort { $packages{ $a }{'order'} <=> $packages{ $b }{'order'} }
 277         keys %packages
 278     ) {
 279         my $pkg = $packages{ $pkg_name };
 280
 281         $create .= join("\n",
 282             $sep,
 283             "package ".$pkg->{'pkg_name'}.";",
 284             "use base '".$pkg->{'base'}."';",
 285             "use Class::DBI::Pager;\n\n",
 286         );
 287
 288 #        if ( $from ) {
 289 #            $create .=
 290 #                $pkg->{'pkg_name'}."->set_up_table('".$pkg->{'table'}."');\n\n";
 291 #        }
 292 #        else {
 293 #            my $table       = $schema->get_table( $pkg->{'table'} );
 294 #            my @field_names = map { $_->name } $table->get_fields;
 295 #
 296 #            $create .= join("\n",
 297 #                $pkg_name."->table('".$pkg->{'table'}."');\n",
 298 #                $pkg_name."->columns(All => qw/".
 299 #                join(' ', @field_names)."/);\n\n",
 300 #            );
 301 #        }
 302
 303
 304                 #the approach here is to do lazy loading on the expensive columns
 305                 #(expensive defined as those columns which require construction of a referenced object)
 306                 #fields which are strictly data (ie, not references) are treated as essential b/c they
 307                 #don't require much time to set up.
 308
 309                 $create .= $pkg_name."->table('".$pkg->{'table'}."');\n";
 310
 311                 #set up primary key field
 312                 if( $pkg->{'_columns_primary'} ) {
 313                   $create .= $pkg_name."->columns(Primary   => qw/".              $pkg->{'_columns_primary'}      ."/);\n";
 314                 } else {
 315                   die "Class::DBI isn't going to like that you don't have a primary key field for table ".$pkg->{'table'};
 316                 }
 317
 318                 #set up non-FK fields to be populated at construction
 319                 if( $pkg->{'_columns_essential'} ) {
 320                   $create .= $pkg_name."->columns(Essential => qw/". join(' ', @{ $pkg->{'_columns_essential'} }) ."/);\n";
 321                 }
 322
 323                 #set up FK fields for lazy loading on request
 324                 if( $pkg->{'_columns_others'} ) {
 325                   $create .= $pkg_name."->columns(Others    => qw/".    join(' ', @{ $pkg->{'_columns_others'}    }) ."/);\n";
 326                 }
 327
 328                 $create .= "\n";
 329
 330         if ( my $pk = $pkg->{'pk_accessor'} ) {
 331             $create .= $pk;
 332         }
 333
 334         if ( my @has_a = @{ $pkg->{'has_a'} || [] } ) {
 335             $create .= $_ for @has_a;
 336         }
 337
 338                 foreach my $has_many_key (keys %{ $pkg->{'has_many'} }){
 339                   if ( my @has_many = @{ $pkg->{'has_many'}{ $has_many_key } || [] } ) {
 340             $create .= $_ for @has_many;
 341                   }
 342                 }
 343     }
 344
 345     $create .= "1;\n";
 346
 347     return $create;
 348 }
 349
 350 1;
 351
 352 # -------------------------------------------------------------------
 353
 354 =pod
 355
 356 =head1 NAME
 357
 358 SQL::Translator::Producer::ClassDBI - create Class::DBI classes from schema
 359
 360 =head1 SYNOPSIS
 361
 362 Use this producer as you would any other from SQL::Translator.  See
 363 L<SQL::Translator> for details.
 364
 365 This package utilizes SQL::Translator's formatting methods
 366 format_package_name(), format_pk_name(), format_fk_name(), and
 367 format_table_name() as it creates classes, one per table in the schema
 368 provided.  An additional base class is also created for database connectivity
 369 configuration.  See L<Class::DBI> for details on how this works.
 370
 371 =head1 AUTHORS
 372
 373 Allen Day E<lt>allenday@ucla.eduE<gt>
 374 Ying Zhang E<lt>zyolive@yahoo.comE<gt>,
 375 Ken Y. Clark E<lt>kclark@cpan.org<gt>.