1 package DBIx::DBSchema;
4 use vars qw(@ISA $VERSION $DEBUG $errstr);
7 use DBIx::DBSchema::_util qw(_load_driver _dbh);
8 use DBIx::DBSchema::Table 0.03;
9 use DBIx::DBSchema::Column;
10 use DBIx::DBSchema::ColGroup::Unique;
11 use DBIx::DBSchema::ColGroup::Index;
21 DBIx::DBSchema - Database-independent schema objects
27 $schema = new DBIx::DBSchema @dbix_dbschema_table_objects;
28 $schema = new_odbc DBIx::DBSchema $dbh;
29 $schema = new_odbc DBIx::DBSchema $dsn, $user, $pass;
30 $schema = new_native DBIx::DBSchema $dbh;
31 $schema = new_native DBIx::DBSchema $dsn, $user, $pass;
33 $schema->save("filename");
34 $schema = load DBIx::DBSchema "filename" or die $DBIx::DBSchema::errstr;
36 $schema->addtable($dbix_dbschema_table_object);
38 @table_names = $schema->tables;
40 $DBIx_DBSchema_table_object = $schema->table("table_name");
42 @sql = $schema->sql($dbh);
43 @sql = $schema->sql($dsn, $username, $password);
44 @sql = $schema->sql($dsn); #doesn't connect to database - less reliable
46 $perl_code = $schema->pretty_print;
47 %hash = eval $perl_code;
48 use DBI qw(:sql_types); $schema = pretty_read DBIx::DBSchema \%hash;
52 DBIx::DBSchema objects are collections of DBIx::DBSchema::Table objects and
53 represent a database schema.
55 This module implements an OO-interface to database schemas. Using this module,
56 you can create a database schema with an OO Perl interface. You can read the
57 schema from an existing database. You can save the schema to disk and restore
58 it a different process. Most importantly, DBIx::DBSchema can write SQL
59 CREATE statements statements for different databases from a single source.
61 Currently supported databases are MySQL and PostgreSQL. Sybase support is
62 partially implemented. DBIx::DBSchema will attempt to use generic SQL syntax
63 for other databases. Assistance adding support for other databases is
64 welcomed. See L<DBIx::DBSchema::DBD>, "Driver Writer's Guide and Base Class".
70 =item new TABLE_OBJECT, TABLE_OBJECT, ...
72 Creates a new DBIx::DBSchema object.
77 my($proto, @tables) = @_;
78 my %tables = map { $_->name, $_ } @tables; #check for duplicates?
80 my $class = ref($proto) || $proto;
85 bless ($self, $class);
89 =item new_odbc DATABASE_HANDLE | DATA_SOURCE USERNAME PASSWORD [ ATTR ]
91 Creates a new DBIx::DBSchema object from an existing data source, which can be
92 specified by passing an open DBI database handle, or by passing the DBI data
93 source name, username, and password. This uses the experimental DBI type_info
94 method to create a schema with standard (ODBC) SQL column types that most
95 closely correspond to any non-portable column types. Use this to import a
96 schema that you wish to use with many different database engines. Although
97 primary key and (unique) index information will only be read from databases
98 with DBIx::DBSchema::DBD drivers (currently MySQL and PostgreSQL), import of
99 column names and attributes *should* work for any database. Note that this
100 method only uses "ODBC" column types; it does not require or use an ODBC
106 my($proto, $dbh) = ( shift, _dbh(@_) );
108 map { new_odbc DBIx::DBSchema::Table $dbh, $_ } _tables_from_dbh($dbh)
112 =item new_native DATABASE_HANDLE | DATA_SOURCE USERNAME PASSWORD [ ATTR ]
114 Creates a new DBIx::DBSchema object from an existing data source, which can be
115 specified by passing an open DBI database handle, or by passing the DBI data
116 source name, username and password. This uses database-native methods to read
117 the schema, and will preserve any non-portable column types. The method is
118 only available if there is a DBIx::DBSchema::DBD for the corresponding database engine (currently, MySQL and PostgreSQL).
123 my($proto, $dbh) = (shift, _dbh(@_) );
125 map { new_native DBIx::DBSchema::Table ( $dbh, $_ ) } _tables_from_dbh($dbh)
131 Loads a DBIx::DBSchema object from a file. If there is an error, returns
132 false and puts an error message in $DBIx::DBSchema::errstr;
137 my($proto,$file)=@_; #use $proto ?
142 eval { $self = Storable::retrieve($file); };
144 if ( $@ && $@ =~ /not.*storable/i ) { #then try FreezeThaw
147 eval "use FreezeThaw;";
152 or do { $errstr = "Can't open $file: $!"; return ''; };
153 my $string = join('',<FILE>);
155 or do { $errstr = "Can't close $file: $!"; return ''; };
156 ($self) = FreezeThaw::thaw($string);
170 Saves a DBIx::DBSchema object to a file.
175 #my($self, $file) = @_;
176 Storable::nstore(@_);
179 =item addtable TABLE_OBJECT
181 Adds the given DBIx::DBSchema::Table object to this DBIx::DBSchema.
187 $self->{'tables'}->{$table->name} = $table; #check for dupliates?
192 Returns a list of the names of all tables.
198 keys %{$self->{'tables'}};
201 =item table TABLENAME
203 Returns the specified DBIx::DBSchema::Table object.
209 $self->{'tables'}->{$table};
212 =item sql [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
214 Returns a list of SQL `CREATE' statements for this schema.
216 The data source can be specified by passing an open DBI database handle, or by
217 passing the DBI data source name, username and password.
219 Although the username and password are optional, it is best to call this method
220 with a database handle or data source including a valid username and password -
221 a DBI connection will be opened and the quoting and type mapping will be more
224 If passed a DBI data source (or handle) such as `DBI:mysql:database' or
225 `DBI:Pg:dbname=database', will use syntax specific to that database engine.
226 Currently supported databases are MySQL and PostgreSQL.
228 If not passed a data source (or handle), or if there is no driver for the
229 specified database, will attempt to use generic SQL syntax.
234 my($self, $dbh) = ( shift, _dbh(@_) );
235 map { $self->table($_)->sql_create_table($dbh); } $self->tables;
238 =item sql_update_schema PROTOTYPE_SCHEMA [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
240 Returns a list of SQL statements to update this schema so that it is idential
241 to the provided prototype schema, also a DBIx::DBSchema object.
243 #Optionally, the data source can be specified by passing an open DBI database
244 #handle, or by passing the DBI data source name, username and password.
246 #If passed a DBI data source (or handle) such as `DBI:mysql:database' or
247 #`DBI:Pg:dbname=database', will use syntax specific to that database engine.
248 #Currently supported databases are MySQL and PostgreSQL.
250 #If not passed a data source (or handle), or if there is no driver for the
251 #specified database, will attempt to use generic SQL syntax.
253 Right now this method knows how to add new tables and alter existing tables.
254 It doesn't know how to drop tables yet.
256 See L<DBIx::DBSchema::Table/sql_alter_table>,
257 L<DBIx::DBSchema::Column/sql_add_coumn> and
258 L<DBIx::DBSchema::Column/sql_alter_column> for additional specifics and
263 #gosh, false laziness w/DBSchema::Table::sql_alter_schema
265 sub sql_update_schema {
266 my($self, $new, $dbh) = ( shift, shift, _dbh(@_) );
270 foreach my $table ( $new->tables ) {
272 if ( $self->table($table) ) {
274 warn "$table exists\n" if $DEBUG > 1;
277 $self->table($table)->sql_alter_table( $new->table($table), $dbh );
281 warn "table $table does not exist.\n" if $DEBUG;
284 $new->table($table)->sql_create_table( $dbh );
290 # should eventually drop tables not in $new
292 warn join("\n", @r). "\n"
299 =item update_schema PROTOTYPE_SCHEMA, DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ]
301 Same as sql_update_schema, except actually runs the SQL commands to update
302 the schema. Throws a fatal error if any statement fails.
307 my($self, $new, $dbh) = ( shift, shift, _dbh(@_) );
309 foreach my $statement ( $self->sql_update_schema( $new, $dbh ) ) {
310 $dbh->do( $statement )
311 or die "Error: ". $dbh->errstr. "\n executing: $statement";
318 Returns the data in this schema as Perl source, suitable for assigning to a
331 #cant because -w complains about , in qw()
332 # (also biiiig problems with empty lengths)
334 #$self->table($table)->column($_)->type. " ".
335 #( $self->table($table)->column($_)->null ? 'NULL' : 0 ). " ".
336 #$self->table($table)->column($_)->length. " ),\n"
338 "'". $self->table($table)->column($_)->type. "', ".
339 "'". $self->table($table)->column($_)->null. "', ".
340 "'". $self->table($table)->column($_)->length. "', ".
341 "'". $self->table($table)->column($_)->default. "', ".
342 "'". $self->table($table)->column($_)->local. "',\n"
343 } $self->table($table)->columns
346 " 'primary_key' => '". $self->table($table)->primary_key. "',\n".
347 " 'unique' => [ ". join(', ',
348 map { "[ '". join("', '", @{$_}). "' ]" }
349 @{$self->table($table)->unique->lol_ref}
351 " 'index' => [ ". join(', ',
352 map { "[ '". join("', '", @{$_}). "' ]" }
353 @{$self->table($table)->index->lol_ref}
355 #" 'index' => [ ". " ],\n"
362 =item pretty_read HASHREF
364 Creates a schema as specified by a data structure such as that created by
365 B<pretty_print> method.
370 my($proto, $href) = @_;
371 my $schema = $proto->new( map {
373 while ( @{$href->{$_}{'columns'}} ) {
374 push @columns, DBIx::DBSchema::Column->new(
375 splice @{$href->{$_}{'columns'}}, 0, 6
378 DBIx::DBSchema::Table->new(
380 $href->{$_}{'primary_key'},
381 DBIx::DBSchema::ColGroup::Unique->new($href->{$_}{'unique'}),
382 DBIx::DBSchema::ColGroup::Index->new($href->{$_}{'index'}),
388 # private subroutines
390 sub _tables_from_dbh {
392 my $driver = _load_driver($dbh);
394 scalar(eval "DBIx::DBSchema::DBD::$driver->default_db_catalog");
396 scalar(eval "DBIx::DBSchema::DBD::$driver->default_db_schema");
397 my $sth = $dbh->table_info($db_catalog, $db_schema, '', 'TABLE')
399 #map { $_->{TABLE_NAME} } grep { $_->{TABLE_TYPE} eq 'TABLE' }
400 # @{ $sth->fetchall_arrayref({ TABLE_NAME=>1, TABLE_TYPE=>1}) };
401 map { $_->[0] } grep { $_->[1] =~ /^TABLE$/i }
402 @{ $sth->fetchall_arrayref([2,3]) };
409 Ivan Kohler <ivan-dbix-dbschema@420.am>
411 Charles Shapiro <charles.shapiro@numethods.com> and Mitchell Friedman
412 <mitchell.friedman@numethods.com> contributed the start of a Sybase driver.
414 Daniel Hanks <hanksdc@about-inc.com> contributed the Oracle driver.
416 Jesse Vincent contributed the SQLite driver.
420 Contributions are welcome! I'm especially keen on any interest in the first
421 three items/projects below under BUGS.
425 Copyright (c) 2000-2006 Ivan Kohler
426 Copyright (c) 2000 Mail Abuse Prevention System LLC
428 This program is free software; you can redistribute it and/or modify it under
429 the same terms as Perl itself.
433 Indices are not stored by name. Index representation could use an overhaul.
435 Multiple primary keys are not yet supported.
437 Foreign keys and other constraints are not yet supported.
439 Eventually it would be nice to have additional transformations (deleted,
440 modified columns, added/modified/indices (probably need em named first),
443 Need to port and test with additional databases
445 Each DBIx::DBSchema object should have a name which corresponds to its name
446 within the SQL database engine (DBI data source).
448 pretty_print is actually pretty ugly.
450 Perhaps pretty_read should eval column types so that we can use DBI
451 qw(:sql_types) here instead of externally.
453 sql CREATE TABLE output should convert integers
454 (i.e. use DBI qw(:sql_types);) to local types using DBI->type_info plus a hash
457 sql_update_schema doesn't drop tables yet.
461 L<DBIx::DBSchema::Table>, L<DBIx::DBSchema::ColGroup>,
462 L<DBIx::DBSchema::ColGroup::Unique>, L<DBIx::DBSchema::ColGroup::Index>,
463 L<DBIx::DBSchema::Column>, L<DBIx::DBSchema::DBD>,
464 L<DBIx::DBSchema::DBD::mysql>, L<DBIx::DBSchema::DBD::Pg>, L<FS::Record>,