Mojo::Pg::Migrations(3pm)

1Mojo::Pg::Migrations(3)User Contributed Perl DocumentatioMnojo::Pg::Migrations(3)
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NAME

6       Mojo::Pg::Migrations - Migrations
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SYNOPSIS

9         use Mojo::Pg::Migrations;
10
11         my $migrations = Mojo::Pg::Migrations->new(pg => $pg);
12         $migrations->from_file('/home/sri/migrations.sql')->migrate;
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DESCRIPTION

15       Mojo::Pg::Migrations is used by Mojo::Pg to allow database schemas to
16       evolve easily over time. A migration file is just a collection of sql
17       blocks, with one or more statements, separated by comments of the form
18       "-- VERSION UP/DOWN".
19
20         -- 1 up
21         create table messages (message text);
22         insert into messages values ('I ♥ Mojolicious!');
23         -- 1 down
24         drop table messages;
25
26         -- 2 up (...you can comment freely here...)
27         create table stuff (whatever int);
28         -- 2 down
29         drop table stuff;
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31       The idea is to let you migrate from any version, to any version, up and
32       down.  Migrations are very safe, because they are performed in
33       transactions and only one can be performed at a time. If a single
34       statement fails, the whole migration will fail and get rolled back.
35       Every set of migrations has a "name", which is stored together with the
36       currently active version in an automatically created table named
37       "mojo_migrations".
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ATTRIBUTES

40       Mojo::Pg::Migrations implements the following attributes.
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42   name
43         my $name    = $migrations->name;
44         $migrations = $migrations->name('foo');
45
46       Name for this set of migrations, defaults to "migrations".
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48   pg
49         my $pg      = $migrations->pg;
50         $migrations = $migrations->pg(Mojo::Pg->new);
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52       Mojo::Pg object these migrations belong to.
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METHODS

55       Mojo::Pg::Migrations inherits all methods from Mojo::Base and
56       implements the following new ones.
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58   active
59         my $version = $migrations->active;
60
61       Currently active version.
62
63   from_data
64         $migrations = $migrations->from_data;
65         $migrations = $migrations->from_data('main');
66         $migrations = $migrations->from_data('main', 'file_name');
67
68       Extract migrations from a file in the DATA section of a class with
69       "data_section" in Mojo::Loader, defaults to using the caller class and
70       "name".
71
72         __DATA__
73         @@ migrations
74         -- 1 up
75         create table messages (message text);
76         insert into messages values ('I ♥ Mojolicious!');
77         -- 1 down
78         drop table messages;
79
80   from_file
81         $migrations = $migrations->from_file('/home/sri/migrations.sql');
82
83       Extract migrations from a file.
84
85   from_string
86         $migrations = $migrations->from_string(
87           '-- 1 up
88            create table foo (bar int);
89            -- 1 down
90            drop table foo;'
91         );
92
93       Extract migrations from string.
94
95   latest
96         my $version = $migrations->latest;
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98       Latest version available.
99
100   migrate
101         $migrations = $migrations->migrate;
102         $migrations = $migrations->migrate(3);
103
104       Migrate from "active" to a different version, up or down, defaults to
105       using "latest". All version numbers need to be positive, with version 0
106       representing an empty database.
107
108         # Reset database
109         $migrations->migrate(0)->migrate;
110
111   sql_for
112         my $sql = $migrations->sql_for(5, 10);
113
114       Get SQL to migrate from one version to another, up or down.
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DEBUGGING

117       You can set the "MOJO_MIGRATIONS_DEBUG" environment variable to get
118       some advanced diagnostics information printed to "STDERR".
119
120         MOJO_MIGRATIONS_DEBUG=1
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NAME

SYNOPSIS

DESCRIPTION

ATTRIBUTES

METHODS

DEBUGGING

SEE ALSO