X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FSchema%2FVersioned.pm;h=6ded2fbbd4c7cf181fba824e77791ab35459105c;hb=e84a43c14a0804314245c9cf872d7af9366efc96;hp=0799202d33e778d3def73f2cdd79a96ec3bf4f87;hpb=5b60f0c107afa5bfac568b691f663e2430df7618;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Schema/Versioned.pm b/lib/DBIx/Class/Schema/Versioned.pm
index 0799202..6ded2fb 100644
--- a/lib/DBIx/Class/Schema/Versioned.pm
+++ b/lib/DBIx/Class/Schema/Versioned.pm
@@ -71,47 +71,108 @@ DBIx::Class::Schema::Versioned - DBIx::Class::Schema plugin for Schema upgrades
 =head1 SYNOPSIS
 
   package Library::Schema;
-  use base qw/DBIx::Class::Schema/;   
+  use base qw/DBIx::Class::Schema/;
+
+  our $VERSION = 0.001;
+
   # load Library::Schema::CD, Library::Schema::Book, Library::Schema::DVD
   __PACKAGE__->load_classes(qw/CD Book DVD/);
 
-  __PACKAGE__->load_components(qw/+DBIx::Class::Schema::Versioned/);
+  __PACKAGE__->load_components(qw/Schema::Versioned/);
   __PACKAGE__->upgrade_directory('/path/to/upgrades/');
-  __PACKAGE__->backup_directory('/path/to/backups/');
 
 
 =head1 DESCRIPTION
 
-This module is a component designed to extend L<DBIx::Class::Schema>
-classes, to enable them to upgrade to newer schema layouts. To use this
-module, you need to have called C<create_ddl_dir> on your Schema to
-create your upgrade files to include with your delivery.
+This module provides methods to apply DDL changes to your database using SQL
+diff files. Normally these diff files would be created using
+L<DBIx::Class::Schema/create_ddl_dir>.
 
 A table called I<dbix_class_schema_versions> is created and maintained by the
-module. This contains two fields, 'Version' and 'Installed', which
-contain each VERSION of your Schema, and the date+time it was installed.
-
-The actual upgrade is called manually by calling C<upgrade> on your
-schema object. Code is run at connect time to determine whether an
-upgrade is needed, if so, a warning "Versions out of sync" is
-produced.
+module. This is used to determine which version your database is currently at.
+Similarly the $VERSION in your DBIC schema class is used to determine the
+current DBIC schema version.
 
-So you'll probably want to write a script which generates your DDLs and diffs
-and another which executes the upgrade.
+The upgrade is initiated manually by calling C<upgrade> on your schema object,
+this will attempt to upgrade the database from its current version to the current
+schema version using a diff from your I<upgrade_directory>. If a suitable diff is
+not found then no upgrade is possible.
 
 NB: At the moment, only SQLite and MySQL are supported. This is due to
 spotty behaviour in the SQL::Translator producers, please help us by
-them.
+enhancing them. Ask on the mailing list or IRC channel for details (details
+in L<DBIx::Class>).
 
-=head1 METHODS
+=head1 GETTING STARTED
 
-=head2 upgrade_directory
+Firstly you need to setup your schema class as per the L</SYNOPSIS>, make sure
+you have specified an upgrade_directory and an initial $VERSION.
 
-Use this to set the directory your upgrade files are stored in.
+Then you'll need two scripts, one to create DDL files and diffs and another to perform
+upgrades. Your creation script might look like a bit like this:
 
-=head2 backup_directory
+  use strict;
+  use Pod::Usage;
+  use Getopt::Long;
+  use MyApp::Schema;
+
+  my ( $preversion, $help ); 
+  GetOptions(
+    'p|preversion:s'  => \$preversion,
+  ) or die pod2usage;
+
+  my $schema = MyApp::Schema->connect(
+    $dsn,
+    $user,
+    $password,
+  );
+  my $sql_dir = './sql';
+  my $version = $schema->schema_version();
+  $schema->create_ddl_dir( 'MySQL', $version, $sql_dir, $preversion );
+
+Then your upgrade script might look like so:
+
+  use strict;
+  use MyApp::Schema;
+
+  my $schema = MyApp::Schema->connect(
+    $dsn,
+    $user,
+    $password,
+  );
+
+  if (!$schema->get_db_version()) {
+    # schema is unversioned
+    $schema->deploy();
+  } else {
+    $schema->upgrade();
+  }
 
-Use this to set the directory you want your backups stored in.
+The script above assumes that if the database is unversioned then it is empty
+and we can safely deploy the DDL to it. However things are not always so simple.
+
+if you want to initialise a pre-existing database where the DDL is not the same
+as the DDL for your current schema version then you will need a diff which 
+converts the database's DDL to the current DDL. The best way to do this is
+to get a dump of the database schema (without data) and save that in your
+SQL directory as version 0.000 (the filename must be as with
+L<DBIx::Class::Schema/ddl_filename>) then create a diff using your create DDL 
+script given above from version 0.000 to the current version. Then hand check
+and if necessary edit the resulting diff to ensure that it will apply. Once you have 
+done all that you can do this:
+
+  if (!$schema->get_db_version()) {
+    # schema is unversioned
+    $schema->install("0.000");
+  }
+
+  # this will now apply the 0.000 to current version diff
+  $schema->upgrade();
+
+In the case of an unversioned database the above code will create the
+dbix_class_schema_versions table and write version 0.000 to it, then 
+upgrade will then apply the diff we talked about creating in the previous paragraph
+and then you're good to go.
 
 =cut
 
@@ -129,128 +190,77 @@ __PACKAGE__->mk_classdata('backup_directory');
 __PACKAGE__->mk_classdata('do_backup');
 __PACKAGE__->mk_classdata('do_diff_on_init');
 
-=head2 get_db_version
 
-Returns the version that your database is currently at. This is determined by the values in the
-dbix_class_schema_versions table that $self->upgrade writes to.
-
-=cut
+=head1 METHODS
 
-sub get_db_version
-{
-    my ($self, $rs) = @_;
+=head2 upgrade_directory
 
-    my $vtable = $self->{vschema}->resultset('Table');
-    my $version = 0;
-    eval {
-      my $stamp = $vtable->get_column('installed')->max;
-      $version = $vtable->search({ installed => $stamp })->first->version;
-    };
-    return $version;
-}
+Use this to set the directory your upgrade files are stored in.
 
-sub _source_exists
-{
-    my ($self, $rs) = @_;
+=head2 backup_directory
 
-    my $c = eval {
-        $rs->search({ 1, 0 })->count;
-    };
-    return 0 if $@ || !defined $c;
+Use this to set the directory you want your backups stored in (note that backups
+are disabled by default).
 
-    return 1;
-}
+=cut
 
-=head2 backup
+=head2 install
 
-This is an overwritable method which is called just before the upgrade, to
-allow you to make a backup of the database. Per default this method attempts
-to call C<< $self->storage->backup >>, to run the standard backup on each
-database type. 
+=over 4
 
-This method should return the name of the backup file, if appropriate..
+=item Arguments: $db_version
 
-This method is disabled by default. Set $schema->do_backup(1) to enable it.
+=back
 
-=cut
+Call this to initialise a previously unversioned database. The table 'dbix_class_schema_versions' will be created which will be used to store the database version.
 
-sub backup
-{
-    my ($self) = @_;
-    ## Make each ::DBI::Foo do this
-    $self->storage->backup($self->backup_directory());
-}
+Takes one argument which should be the version that the database is currently at. Defaults to the return value of L</schema_version>.
 
-# is this just a waste of time? if not then merge with DBI.pm
-sub _create_db_to_schema_diff {
-  my $self = shift;
+See L</getting_started> for more details.
 
-  my %driver_to_db_map = (
-                          'mysql' => 'MySQL'
-                         );
+=cut
 
-  my $db = $driver_to_db_map{$self->storage->dbh->{Driver}->{Name}};
-  unless ($db) {
-    print "Sorry, this is an unsupported DB\n";
-    return;
-  }
+sub install
+{
+  my ($self, $new_version) = @_;
 
-  eval 'require SQL::Translator "0.09"';
-  if ($@) {
-    $self->throw_exception("SQL::Translator 0.09 required");
+  # must be called on a fresh database
+  if ($self->get_db_version()) {
+    warn 'Install not possible as versions table already exists in database';
   }
 
-  my $db_tr = SQL::Translator->new({ 
-                                    add_drop_table => 1, 
-                                    parser => 'DBI',
-                                    parser_args => { dbh => $self->storage->dbh }
-                                   });
-
-  $db_tr->producer($db);
-  my $dbic_tr = SQL::Translator->new;
-  $dbic_tr->parser('SQL::Translator::Parser::DBIx::Class');
-  $dbic_tr = $self->storage->configure_sqlt($dbic_tr, $db);
-  $dbic_tr->data($self);
-  $dbic_tr->producer($db);
-
-  $db_tr->schema->name('db_schema');
-  $dbic_tr->schema->name('dbic_schema');
+  # default to current version if none passed
+  $new_version ||= $self->schema_version();
 
-  # is this really necessary?
-  foreach my $tr ($db_tr, $dbic_tr) {
-    my $data = $tr->data;
-    $tr->parser->($tr, $$data);
+  if ($new_version) {
+    # create versions table and version row
+    $self->{vschema}->deploy;
+    $self->_set_db_version;
   }
+}
 
-  my $diff = SQL::Translator::Diff::schema_diff($db_tr->schema, $db, 
-                                                $dbic_tr->schema, $db,
-                                                { ignore_constraint_names => 1, ignore_index_names => 1, caseopt => 1 });
+=head2 deploy
 
-  my $filename = $self->ddl_filename(
-                                         $db,
-                                         $self->schema_version,
-                                         $self->upgrade_directory,
-                                         'PRE',
-                                    );
-  my $file;
-  if(!open($file, ">$filename"))
-    {
-      $self->throw_exception("Can't open $filename for writing ($!)");
-      next;
-    }
-  print $file $diff;
-  close($file);
+Same as L<DBIx::Class::Schema/deploy> but also calls C<install>.
 
-  print "WARNING: There may be differences between your DB and your DBIC schema. Please review and if necessary run the SQL in $filename to sync your DB.\n";
+=cut
+
+sub deploy {
+  my $self = shift;
+  $self->next::method(@_);
+  $self->install();
 }
 
 =head2 upgrade
 
 Call this to attempt to upgrade your database from the version it is at to the version
-this DBIC schema is at. 
+this DBIC schema is at. If they are the same it does nothing.
 
-It requires an SQL diff file to exist in $schema->upgrade_directory, normally you will
-have created this using $schema->create_ddl_dir.
+It requires an SQL diff file to exist in you I<upgrade_directory>, normally you will
+have created this using L<DBIx::Class::Schema/create_ddl_dir>.
+
+If successful the dbix_class_schema_versions table is updated with the current
+DBIC schema version.
 
 =cut
 
@@ -261,12 +271,7 @@ sub upgrade
 
   # db unversioned
   unless ($db_version) {
-    # set version in dbix_class_schema_versions table, can't actually upgrade as we don 't know what version the DB is at
-    $self->_create_db_to_schema_diff() if ($self->do_diff_on_init);
-
-    # create versions table and version row
-    $self->{vschema}->deploy;
-    $self->_set_db_version;
+    warn 'Upgrade not possible as database is unversioned. Please call install first.';
     return;
   }
 
@@ -303,31 +308,6 @@ sub upgrade
   $self->_set_db_version;
 }
 
-sub _set_db_version {
-  my $self = shift;
-
-  my $vtable = $self->{vschema}->resultset('Table');
-  $vtable->create({ version => $self->schema_version,
-                      installed => strftime("%Y-%m-%d %H:%M:%S", gmtime())
-                      });
-
-}
-
-sub _read_sql_file {
-  my $self = shift;
-  my $file = shift || return;
-
-  my $fh;
-  open $fh, "<$file" or warn("Can't open upgrade file, $file ($!)");
-  my @data = split(/\n/, join('', <$fh>));
-  @data = grep(!/^--/, @data);
-  @data = split(/;/, join('', @data));
-  close($fh);
-  @data = grep { $_ && $_ !~ /^-- / } @data;
-  @data = grep { $_ !~ /^(BEGIN TRANSACTION|COMMIT)/m } @data;
-  return \@data;
-}
-
 =head2 do_upgrade
 
 This is an overwritable method used to run your upgrade. The freeform method
@@ -353,7 +333,7 @@ sub do_upgrade
 
 Runs a set of SQL statements matching a passed in regular expression. The
 idea is that this method can be called any number of times from your
-C<upgrade> method, running whichever commands you specify via the
+C<do_upgrade> method, running whichever commands you specify via the
 regex in the parameter. Probably won't work unless called from the overridable
 do_upgrade method.
 
@@ -377,6 +357,52 @@ sub run_upgrade
     return 1;
 }
 
+=head2 get_db_version
+
+Returns the version that your database is currently at. This is determined by the values in the
+dbix_class_schema_versions table that C<upgrade> and C<install> write to.
+
+=cut
+
+sub get_db_version
+{
+    my ($self, $rs) = @_;
+
+    my $vtable = $self->{vschema}->resultset('Table');
+    my $version = 0;
+    eval {
+      my $stamp = $vtable->get_column('installed')->max;
+      $version = $vtable->search({ installed => $stamp })->first->version;
+    };
+    return $version;
+}
+
+=head2 schema_version
+
+Returns the current schema class' $VERSION
+
+=cut
+
+=head2 backup
+
+This is an overwritable method which is called just before the upgrade, to
+allow you to make a backup of the database. Per default this method attempts
+to call C<< $self->storage->backup >>, to run the standard backup on each
+database type. 
+
+This method should return the name of the backup file, if appropriate..
+
+This method is disabled by default. Set $schema->do_backup(1) to enable it.
+
+=cut
+
+sub backup
+{
+    my ($self) = @_;
+    ## Make each ::DBI::Foo do this
+    $self->storage->backup($self->backup_directory());
+}
+
 =head2 connection
 
 Overloaded method. This checks the DBIC schema version against the DB version and
@@ -384,7 +410,7 @@ warns if they are not the same or if the DB is unversioned. It also provides
 compatibility between the old versions table (SchemaVersions) and the new one
 (dbix_class_schema_versions).
 
-To avoid the checks on connect, set the env var DBIC_NO_VERSION_CHECK or alternatively you can set the ignore_version attr in the forth arg like so:
+To avoid the checks on connect, set the env var DBIC_NO_VERSION_CHECK or alternatively you can set the ignore_version attr in the forth argument like so:
 
   my $schema = MyApp::Schema->connect(
     $dsn,
@@ -441,6 +467,107 @@ sub _on_connect
     ", your database contains version $pversion, please call upgrade on your Schema.\n";
 }
 
+# is this just a waste of time? if not then merge with DBI.pm
+sub _create_db_to_schema_diff {
+  my $self = shift;
+
+  my %driver_to_db_map = (
+                          'mysql' => 'MySQL'
+                         );
+
+  my $db = $driver_to_db_map{$self->storage->dbh->{Driver}->{Name}};
+  unless ($db) {
+    print "Sorry, this is an unsupported DB\n";
+    return;
+  }
+
+  eval 'require SQL::Translator "0.09"';
+  if ($@) {
+    $self->throw_exception("SQL::Translator 0.09 required");
+  }
+
+  my $db_tr = SQL::Translator->new({ 
+                                    add_drop_table => 1, 
+                                    parser => 'DBI',
+                                    parser_args => { dbh => $self->storage->dbh }
+                                   });
+
+  $db_tr->producer($db);
+  my $dbic_tr = SQL::Translator->new;
+  $dbic_tr->parser('SQL::Translator::Parser::DBIx::Class');
+  $dbic_tr = $self->storage->configure_sqlt($dbic_tr, $db);
+  $dbic_tr->data($self);
+  $dbic_tr->producer($db);
+
+  $db_tr->schema->name('db_schema');
+  $dbic_tr->schema->name('dbic_schema');
+
+  # is this really necessary?
+  foreach my $tr ($db_tr, $dbic_tr) {
+    my $data = $tr->data;
+    $tr->parser->($tr, $$data);
+  }
+
+  my $diff = SQL::Translator::Diff::schema_diff($db_tr->schema, $db, 
+                                                $dbic_tr->schema, $db,
+                                                { ignore_constraint_names => 1, ignore_index_names => 1, caseopt => 1 });
+
+  my $filename = $self->ddl_filename(
+                                         $db,
+                                         $self->schema_version,
+                                         $self->upgrade_directory,
+                                         'PRE',
+                                    );
+  my $file;
+  if(!open($file, ">$filename"))
+    {
+      $self->throw_exception("Can't open $filename for writing ($!)");
+      next;
+    }
+  print $file $diff;
+  close($file);
+
+  print "WARNING: There may be differences between your DB and your DBIC schema. Please review and if necessary run the SQL in $filename to sync your DB.\n";
+}
+
+
+sub _set_db_version {
+  my $self = shift;
+
+  my $vtable = $self->{vschema}->resultset('Table');
+  $vtable->create({ version => $self->schema_version,
+                      installed => strftime("%Y-%m-%d %H:%M:%S", gmtime())
+                      });
+
+}
+
+sub _read_sql_file {
+  my $self = shift;
+  my $file = shift || return;
+
+  my $fh;
+  open $fh, "<$file" or warn("Can't open upgrade file, $file ($!)");
+  my @data = split(/\n/, join('', <$fh>));
+  @data = grep(!/^--/, @data);
+  @data = split(/;/, join('', @data));
+  close($fh);
+  @data = grep { $_ && $_ !~ /^-- / } @data;
+  @data = grep { $_ !~ /^(BEGIN|BEGIN TRANSACTION|COMMIT)/m } @data;
+  return \@data;
+}
+
+sub _source_exists
+{
+    my ($self, $rs) = @_;
+
+    my $c = eval {
+        $rs->search({ 1, 0 })->count;
+    };
+    return 0 if $@ || !defined $c;
+
+    return 1;
+}
+
 1;