lib/SQL/Translator/Producer/ClassDBI.pm

   1 package SQL::Translator::Producer::ClassDBI;
   2
   3 # -------------------------------------------------------------------
   4 # $Id: ClassDBI.pm,v 1.27 2003-07-09 06:09:56 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: 1.27 $ =~ /(\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 }{'pk_accessor'} =
 125                     "#\n# Primary key accessor\n#\n".
 126                     "sub $pk_name {\n    shift->$field\n}\n\n"
 127                 ;
 128             }
 129         }
 130
 131         #
 132         # Use foreign keys to set up "has_a/has_many" relationships.
 133         #
 134         my $is_data = 0;
 135         foreach my $field ( $table->get_fields ) {
 136             $is_data++ if !$field->is_foreign_key and !$field->is_primary_key;
 137             if ( $field->is_foreign_key ) {
 138                 my $table_name = $table->name;
 139                 my $field_name = $field->name;
 140                 my $fk_method  = $t->format_fk_name($table_name, $field_name);
 141                 my $fk         = $field->foreign_key_reference;
 142                 my $ref_table  = $fk->reference_table;
 143                 my $ref_pkg    = $t->format_package_name($ref_table);
 144                 my $ref_field  = ($fk->reference_fields)[0];
 145
 146                 push @{ $packages{ $table_pkg_name }{'has_a'} },
 147                     "$table_pkg_name->has_a(\n".
 148                     "    $field_name => '$ref_pkg'\n);\n\n".
 149                     "sub $fk_method {\n".
 150                     "    return shift->$field_name\n}\n\n"
 151                 ;
 152
 153                 #
 154                 # If this table "has a" to the other, then it follows
 155                 # that the other table "has many" of this one, right?
 156                 #
 157                                 # No... there is the possibility of 1-1 cardinality
 158                 push @{ $packages{ $ref_pkg }{'has_many'} },
 159                     "$ref_pkg->has_many(\n    '${table_name}_${field_name}', ".
 160                     "'$table_pkg_name' => '$field_name'\n);\n\n"
 161                 ;
 162             }
 163                 }
 164
 165          my %linked;
 166          if ( $is_data ) {
 167              foreach my $link ( keys %{ $linkable{ $table_name } } ) {
 168                            my $linkmethodname;
 169
 170                            # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 171                            if ( my $fk_xform = $t->format_fk_name ){
 172                                  $linkmethodname = $fk_xform->($linkable{$table_name}{$link}->name,
 173                                    ($schema->get_table($link)->primary_key->fields)[0]).'s';
 174                            } else {
 175                                  $linkmethodname = $linkable{$table_name}{$link}->name.'_'.
 176                                    ($schema->get_table($link)->primary_key->fields)[0].'s';
 177                            }
 178
 179 #$create .= $field->name. "\n";
 180 #$create .= $field->foreign_key_reference->reference_table. "\n";
 181 #$create .= $linkable{ $table_name }{ $link }->name. "\n";
 182 #$create .= $table_name. "\n";
 183 #$create .= $link. "\n";
 184 #$create .= "***\n\n";
 185
 186                            my @rk_fields = ();
 187                            my @lk_fields = ();
 188                            foreach my $field ($linkable{$table_name}{$link}->get_fields){
 189                                  next unless $field->is_foreign_key;
 190
 191                                  next unless(
 192                                                          $field->foreign_key_reference->reference_table eq $table_name
 193                                                          ||
 194                                                          $field->foreign_key_reference->reference_table eq $link
 195                                                         );
 196                                  push @lk_fields, ($field->foreign_key_reference->reference_fields)[0]
 197                                    if $field->foreign_key_reference->reference_table eq $link;
 198                                  push @rk_fields, $field->name
 199                                    if $field->foreign_key_reference->reference_table eq $table_name;
 200                            }
 201
 202                            #if one possible traversal via link table
 203                            if(scalar(@rk_fields) == 1 and scalar(@lk_fields) == 1){
 204                                  foreach my $rk_field (@rk_fields){
 205                                    push @{ $packages{ $table_pkg_name }{'has_many'} },
 206                                          "sub ".$linkmethodname." { my \$self = shift; ".
 207                                            "return map \$_->".
 208                                                  ($schema->get_table($link)->primary_key->fields)[0].
 209                                                    ", \$self->".$linkable{$table_name}{$link}->name.
 210                                                          "_".$rk_field." }\n\n";
 211                                  }
 212                            #else there is more than one way to traverse it.  ack!
 213                            #let's treat these types of link tables as a many-to-one (easier)
 214                            #
 215                            #NOTE: we need to rethink the link method name, as the cardinality
 216                            #has shifted on us.
 217                            } elsif(scalar(@rk_fields) == 1){
 218                                  foreach my $rk_field (@rk_fields){
 219                                    push @{ $packages{ $table_pkg_name }{'has_many'} },
 220                                          "sub " . $linkable{$table_name}{$link}->name .
 221                                            "s { my \$self = shift; return \$self->" .
 222                                                  $linkable{$table_name}{$link}->name . "_" .
 223                                                    $rk_field . "(\@_) }\n\n";
 224                                  }
 225                            } elsif(scalar(@lk_fields) == 1){
 226                                  #these will be taken care of on the other end...
 227                            } else {
 228                                  #many many many.  need multiple iterations here, data structure revision
 229                                  #to handle N FK sources
 230                                  foreach my $rk_field (@rk_fields){
 231                                    push @{ $packages{ $table_pkg_name }{'has_many'} },
 232                                          "sub " . $linkable{$table_name}{$link}->name . "_" . $rk_field .
 233                                            "s { my \$self = shift; return \$self->" .
 234                                                  $linkable{$table_name}{$link}->name . "_" .
 235                                                    $rk_field . "(\@_) }\n\n";
 236                                  }
 237                            }
 238             }
 239         }
 240     }
 241
 242     #
 243     # Now build up text of package.
 244     #
 245     my $base_pkg = sprintf( 'Class::DBI%s', $from ? "::$from" : '' );
 246     $create .= join("\n",
 247       "package $main_pkg_name;\n",
 248       $header,
 249       "use strict;",
 250       "use base '$base_pkg';\n",
 251       "$main_pkg_name->set_db('Main', '$dsn', '$db_user', '$db_pass');\n\n",
 252     );
 253
 254     for my $pkg_name (
 255         sort { $packages{ $a }{'order'} <=> $packages{ $b }{'order'} }
 256         keys %packages
 257     ) {
 258         my $pkg = $packages{ $pkg_name };
 259
 260         $create .= join("\n",
 261             $sep,
 262             "package ".$pkg->{'pkg_name'}.";",
 263             "use base '".$pkg->{'base'}."';",
 264             "use Class::DBI::Pager;\n\n",
 265         );
 266
 267         if ( $from ) {
 268             $create .=
 269                 $pkg->{'pkg_name'}."->set_up_table('".$pkg->{'table'}."');\n\n";
 270         }
 271         else {
 272             my $table       = $schema->get_table( $pkg->{'table'} );
 273             my @field_names = map { $_->name } $table->get_fields;
 274
 275             $create .= join("\n",
 276                 $pkg_name."->table('".$pkg->{'table'}."');\n",
 277                 $pkg_name."->columns(All => qw/".
 278                 join(' ', @field_names)."/);\n\n",
 279             );
 280         }
 281
 282         if ( my $pk = $pkg->{'pk_accessor'} ) {
 283             $create .= $pk;
 284         }
 285
 286         if ( my @has_a = @{ $pkg->{'has_a'} || [] } ) {
 287             $create .= $_ for @has_a;
 288         }
 289
 290         if ( my @has_many = @{ $pkg->{'has_many'} || [] } ) {
 291             $create .= $_ for @has_many;
 292         }
 293     }
 294
 295     $create .= "1;\n";
 296
 297     return $create;
 298 }
 299
 300 1;
 301
 302 # -------------------------------------------------------------------
 303
 304 =pod
 305
 306 =head1 NAME
 307
 308 SQL::Translator::Producer::ClassDBI - create Class::DBI classes from schema
 309
 310 =head1 SYNOPSIS
 311
 312 Use this producer as you would any other from SQL::Translator.  See
 313 L<SQL::Translator> for details.
 314
 315 This package utilizes SQL::Translator's formatting methods
 316 format_package_name(), format_pk_name(), format_fk_name(), and
 317 format_table_name() as it creates classes, one per table in the schema
 318 provided.  An additional base class is also created for database connectivity
 319 configuration.  See L<Class::DBI> for details on how this works.
 320
 321 =head1 AUTHORS
 322
 323 Allen Day E<lt>allenday@ucla.eduE<gt>
 324 Ying Zhang E<lt>zyolive@yahoo.comE<gt>,
 325 Ken Y. Clark E<lt>kclark@cpan.org<gt>.