DBIx::Migration::Directories::Base - Schema-independant migration operations


  my $object = DBIx::Migration::Directories::Base->new(
    $dbh => $some_database_handle

  my $schemas = $object->schemas;
  if(my $schema = $schemas->{'Foo-Schema'}) {
     print "Foo-Schema is installed at version #$schema->{version}.\n";


DBIx::Migration::Directories::Base is the base class to DBIx::Migration::Directories.

The methods in this class do not care if you are currently operating on a schema, or if you have a valid schema directory to work with.

The main reason to create DBIx::Migration::Directories::Base object on it's own is to obtain general information about migrations, such as currently installed schemas and their version history.




Creates a new DBIx::Migration::Directories::Base object. %args is a hash of properties to set on the object; the following properties are used by DBIx::Migration::Directories::Base:


Required. The DBIx::Transaction database handle to use for queries. This handle should already be connected to the database that you wish to manage.


The schema we wish to operate on. This option is only ever used by the schema_version_log method, and only if you do not send that method a schema argument.

High-Level Methods


Queries the migration schema, and returns a hash reference containing all of the schemas currently registered in this database. The keys in this hash are the schemas' names, and the values are hash references, containing the contents of that schema's row in the database as key/value pairs:


The schema's name, again.


The current version of this schema.


Queries the migration schema, and returns an array reference containing the specified schema's version history. If a schema is not specified, defaults to the "schema" property if it has been set, otherwise an exception is raised.

Each entry in the array reference returned is a hash reference, containing the contents of that schema's log rows in the database as key/value pairs:


Schema this log entry refers to.


Time this migration action took place.


Schema version before this migration action took place.


Schema version after this migration took place.

Low-Level Methods

direction($from, $to)

Given two version numbers, determine whether this is an upgrade or a downgrade. All this does is:

   $to <=> $from

Given the name of a directory, determine what versions it is migrating from and to. Returns an array of two numbers: the "from" version and the "two" version.

If this directory has two version numbers in it, you'll get those two (normalized) version numbers back. If this directory only has one version number in it, you'll get 0 as the "from" version, and the (normalized) version number in the directory name as the "to" version.


Begin a transaction, and run all of the SQL statements specified in @sql. If any of them fail, roll the transaction back and return 0. If they all succeed, commit the transaction and return 1.


Reads a file on the filesystem and returns it's contents as a scalar. Raises an exception if the file could not be read. Exciting, huh?


Normalize a version number. Currently, this is just equivalent to:

  return $version + 0

But in future releases it may do fancier stuff, like dealing with "double-dot" version numbers or the like.


Tyler "Crackerjack" MacDonald <>


Copyright 2009 Tyler "Crackerjack" MacDonald <>

This is free software; You may distribute it under the same terms as perl itself.



1 POD Error

The following errors were encountered while parsing the POD:

Around line 257:

You forgot a '=back' before '=head2'