NAME

DBI::Schema::Migration - An easy way to start using migrations.

VERSION

version 1.00

SYNOPSIS

use DBI; # it is assumed that you are using DBI to handle your database connections
use DBI::Schema::Migration;

my $driver   = "SQLite"; # just example, you can use mysql, postgres e.t.c
my $database = "test.db";
my $dsn      = "DBI:$driver:dbname=$database";
my $userid   = "";
my $password = "";
my $dbh =
    DBI->connect($dsn, $userid, $password, { RaiseError => 1 }) 
    or die $DBI::errstr;

$migration = DBI::Schema::Migration->new( {
    dbh => $dbh, # connection handler
    dir => 'db/migrations', # path to directory with migrations
} );

$migration->init(); # create applied_migrations table

$migration->up(1);   # run 1 migration
$migration->up();    # run all migrations

$migration->down(1); # rollback 1 migration
$migration->down();  # rollback all migrations

DESCRIPTION

Schema migration is a tool that helps to apply incremental and reversible changes to you relational database. You could build cli util or use this class whintin yor ci/cd script. This module relies on DBI and the database connection it creates. It only works with migrations written in sql.

Migration in terms of this module is a directory consisting of two files: 1 *_up.sql - apply changes 2 *_down.sql - reverse changes

Example: migrations/ | |-- 01_create_table_users/ | \ | \-- 01_create_table_users_up.sql | | | |-- 01_create_table_users_down.sql | |-- 02_add_users/ | \ | \-- 02_add_users_up.sql | | | |-- 02_add_users_down.sql

As you can see, there are some naming conventions: 1 Migrations starts with a number that determines the order 2 Migrations ends with up.sql or down.sql

Once a migration has been applied, it is stored in the database, and the migration will not be applied again, until your reverse it with down method.

CONFIGURATION

dbh - database handler

dir - path to migrations directory, full or relative

METHODS

up($num)

Will apply $num migrations or all of them if $num is not specified.

down($num)

Will reverse $num migrations or all of them if $num is not specified.

BUGS

If you find one, please let me know.

SOURCE CODE REPOSITORY

https://github.com/AlexP007/DBI-Migration - fork or add pr.

AUTHOR

Alexander Panteleev <alexpan at cpan dot org>.

COPYRIGHT AND LICENSE

This software is copyright (c) 2021 by Alexander Panteleev.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.