2 DBIx::Class::Schema::Loader - Dynamic definition of a
7 use base qw/DBIx::Class::Schema::Loader/;
9 __PACKAGE__->loader_options(
10 constraint => '^foo.*',
14 # in seperate application code ...
18 my $schema1 = My::Schema->connect( $dsn, $user, $password, $attrs);
20 my $schema1 = "My::Schema"; $schema1->connection(as above);
23 DBIx::Class::Schema::Loader automates the definition of a
24 DBIx::Class::Schema by scanning database table definitions and setting
25 up the columns, primary keys, and relationships.
27 DBIx::Class::Schema::Loader currently supports only the DBI storage
28 type. It has explicit support for DBD::Pg, DBD::mysql, DBD::DB2,
29 DBD::SQLite, and DBD::Oracle. Other DBI drivers may function to a
30 greater or lesser degree with this loader, depending on how much of the
31 DBI spec they implement, and how standard their implementation is.
33 Patches to make other DBDs work correctly welcome.
35 See DBIx::Class::Schema::Loader::DBI::Writing for notes on writing your
36 own vendor-specific subclass for an unsupported DBD driver.
38 This module requires DBIx::Class 0.07006 or later, and obsoletes the
39 older DBIx::Class::Loader.
41 This module is designed more to get you up and running quickly against
42 an existing database, or to be effective for simple situations, rather
43 than to be what you use in the long term for a complex database/project.
45 That being said, transitioning your code from a Schema generated by this
46 module to one that doesn't use this module should be straightforward and
47 painless, so don't shy away from it just for fears of the transition
52 Example in Synopsis above demonstrates a few common arguments. For
53 detailed information on all of the arguments, most of which are only
54 useful in fairly complex scenarios, see the
55 DBIx::Class::Schema::Loader::Base documentation.
57 If you intend to use "loader_options", you must call "loader_options"
58 before any connection is made, or embed the "loader_options" in the
59 connection information itself as shown below. Setting "loader_options"
60 after the connection has already been made is useless.
63 See DBIx::Class::Schema for basic usage.
65 If the final argument is a hashref, and it contains a key
66 "loader_options", that key will be deleted, and its value will be used
67 for the loader options, just as if set via the "loader_options" method
70 The actual auto-loading operation (the heart of this module) will be
71 invoked as soon as the connection information is defined.
74 See DBIx::Class::Schema.
77 Argument: directory name.
79 Calling this as a class method on either DBIx::Class::Schema::Loader or
80 any derived schema class will cause all affected schemas to dump manual
81 versions of themselves to the named directory when they are loaded. In
82 order to be effective, this must be set before defining a connection on
83 this schema class or any derived object (as the loading happens as soon
84 as both a connection and loader_options are set, and only once per
87 See "dump_directory" in DBIx::Class::Schema::Loader::Base for more
88 details on the dumping mechanism.
90 This can also be set at module import time via the import option
91 "dump_to_dir:/foo/bar" to DBIx::Class::Schema::Loader, where "/foo/bar"
92 is the target directory.
96 # My::Schema isa DBIx::Class::Schema::Loader, and has connection info
97 # hardcoded in the class itself:
98 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e1
100 # Same, but no hard-coded connection, so we must provide one:
101 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e 'My::Schema->connection("dbi:Pg:dbname=foo", ...)'
103 # Or as a class method, as long as you get it done *before* defining a
104 # connection on this schema class or any derived object:
106 My::Schema->dump_to_dir('/foo/bar');
107 My::Schema->connection(........);
109 # Or as a class method on the DBIx::Class::Schema::Loader itself, which affects all
113 DBIx::Class::Schema::Loader->dump_to_dir('/foo/bar');
114 My::Schema->connection(.......);
115 My::OtherSchema->connection(.......);
117 # Another alternative to the above:
118 use DBIx::Class::Schema::Loader qw| dump_to_dir:/foo/bar |;
121 My::Schema->connection(.......);
122 My::OtherSchema->connection(.......);
125 This simple function allows one to create a Loader-based schema
126 in-memory on the fly without any on-disk class files of any kind. When
127 used with the "dump_directory" option, you can use this to generate a
128 rough draft manual schema from a dsn without the intermediate step of
129 creating a physical Loader-based schema class.
131 The return value is the input class name.
133 This function can be exported/imported by the normal means, as
134 illustrated in these Examples:
136 # Simple example, creates as a new class 'New::Schema::Name' in
137 # memory in the running perl interpreter.
138 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
142 [ 'dbi:Pg:dbname="foo"','postgres' ],
145 # Complex: dump loaded schema to disk, all from the commandline:
146 perl -MDBIx::Class::Schema::Loader=make_schema_at,dump_to_dir:./lib -e 'make_schema_at("New::Schema::Name", { debug => 1 }, [ "dbi:Pg:dbname=foo","postgres" ])'
148 # Same, but inside a script, and using a different way to specify the
150 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
153 { debug => 1, dump_directory => './lib' },
154 [ 'dbi:Pg:dbname="foo"','postgres' ],
158 Re-scans the database for newly added tables since the initial load, and
159 adds them to the schema at runtime, including relationships, etc. Does
160 not process drops or changes.
162 Returns a list of the new monikers added.
165 Using the example in DBIx::Class::Manual::ExampleSchema as a basis
166 replace the DB::Main with the following code:
170 use base qw/DBIx::Class::Schema::Loader/;
172 __PACKAGE__->loader_options(
175 __PACKAGE__->connection('dbi:SQLite:example.db');
179 and remove the Main directory tree (optional). Every thing else should
183 Multiple Database Schemas
184 Currently the loader is limited to working within a single schema (using
185 the database vendors' definition of "schema"). If you have a
186 multi-schema database with inter-schema relationships (which is easy to
187 do in PostgreSQL or DB2 for instance), you only get to automatically
188 load the tables of one schema, and any relationships to tables in other
189 schemas will be silently ignored.
191 At some point in the future, an intelligent way around this might be
192 devised, probably by allowing the "db_schema" option to be an arrayref
195 In "normal" DBIx::Class::Schema usage, manually-defined source classes
196 and relationships have no problems crossing vendor schemas.
199 Brandon Black, "blblack@gmail.com"
201 Based on DBIx::Class::Loader by Sebastian Riedel
203 Based upon the work of IKEBE Tomohiro
206 Matt S Trout, all of the #dbix-class folks, and everyone who's ever sent
207 in a bug report or suggestion.
210 This library is free software; you can redistribute it and/or modify it
211 under the same terms as Perl itself.
214 DBIx::Class, DBIx::Class::Manual::ExampleSchema