1 package DBIx::Class::DeploymentHandler::Manual::Intro
3 # ABSTRACT: Introduction to DBIx::Class::DeploymentHandler
7 =head1 Why is DBIx::Class::DeploymentHandler worth using?
9 The most obvious reasons for using DBIx::Class::DeploymentHandler are
10 that it can run multiple SQL scripts as well as Perl scripts, unlike
11 DBIx::Class::Schema::Versioned, which only allows for a single SQL script.
12 It is also extremely extensible, and is an opportunity for a break from
13 backwards compatibility, so some regrettable decisions are avoided.
15 =head1 Sample database
17 Follow L<DBIx::Class::Manual::Intro> except for the parts setting up the
18 database. After you are done, You should have the following files.
29 Add a line like the following in your MyDatabase::Main file:
33 or if you are using a newer Perl you can use the prettier syntax:
35 package MyDatabase::Main 1;
37 By default DBIx::Class::DeploymentHandler only uses integers for versions,
38 this makes versioning much simpler for figuring out what version is next
43 Our first script, C<install.pl> reads our schema file and creates the tables
50 use aliased 'DBIx::Class::DeploymentHandler' => 'DH';
53 use lib "$FindBin::Bin/../lib";
56 my $force_overwrite = 0;
58 unless ( GetOptions( 'force_overwrite!' => \$force_overwrite ) ) {
59 die "Invalid options";
62 my $schema = MyDatabase::Main->connect('dbi:SQLite:mydb.db');
67 script_directory => "$FindBin::Bin/../dbicdh",
68 databases => 'SQLite',
69 sql_translator_args => { add_drop_table => 0 },
70 force_overwrite => $force_overwrite,
77 =head2 dbicdh - Our migration scripts
79 Running C<install.pl> should create the following:
93 DBIx::Class::DeploymentHandler automatically generates SQL from our schema
94 that is suitable for SQLite
98 This contains all of the raw information about our schema that is then
99 translated into the sql.
103 To truly take advantage of all DBIx::Class::DeploymentHandler offers, you
104 should probably be using it for population. To do that all you need to do
105 is create a file called C<dbicdh/_common/deploy/1/create_artists.pl>:
109 $schema->resultset('Artist')->populate([
110 ['artistid', 'name'],
112 [2, 'The Moutain Goats'],
119 Add a line to MyDatabase/Main/Result/Cd.pm below
121 __PACKAGE__->add_columns(qw/ cdid artist title /);
125 __PACKAGE__->add_column(isbn => { is_nullable => 1 });
127 Aside: It must be nullable or have a default - otherwise the upgrade will
128 fail for logical reasons. To be clear, if you add a column to a database and
129 it is not nullable and has no default, what will the existing rows contain
132 Now you need to modify the schema version in your MyDatabase::Main file to
133 tell DBIx::Class::DeploymentHandler the new schema version number. You will
134 want to remember the earlier advice about integer version numbers.
138 So here is our next script, C<upgrade.pl>:
143 use aliased 'DBIx::Class::DeploymentHandler' => 'DH';
145 use lib "$FindBin::Bin/../lib";
146 use MyDatabase::Main;
147 my $schema = MyDatabase::Main->connect('dbi:SQLite:mydb');
151 script_directory => "$FindBin::Bin/dbicdh",
152 databases => 'SQLite',
153 sql_translator_args => { add_drop_table => 0 },
157 $dh->prepare_upgrade({ from_version => 1, to_version => 2});
160 Our script directory now looks like:
166 | | | `-- 001-auto.sql
179 The new C<deploy/001-auto.sql> and C<deploy/001-auto.yml> files are the
180 state of the db as at that version. The C<upgrade/1-2/001-auto.sql> file
181 is the most interesting one; it is what gets your database from version 1 to 2.
183 And again, you can create a Perl file like we did previously with the