From: Arthur Axel 'fREW' Schmidt Date: Sat, 10 Jul 2010 07:11:48 +0000 (-0500) Subject: feature doc map X-Git-Tag: v0.08124~58 X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=9ba33dac83e74b37b5bde62f0f9da4cf22c0e7e4;p=dbsrgits%2FDBIx-Class.git feature doc map --- diff --git a/Changes b/Changes index b0e0a2a..8b9c106 100644 --- a/Changes +++ b/Changes @@ -20,6 +20,8 @@ Revision history for DBIx::Class - $rs->pager now uses a lazy count to determine the amount of total entries only when really needed, instead of doing it at instantiation time + - New documentation map organized by features + (DBIx::Class::Manual::Features) * Fixes - Fix memory leak during populate() on 5.8.x perls diff --git a/lib/DBIx/Class/Manual/Features.pod b/lib/DBIx/Class/Manual/Features.pod new file mode 100644 index 0000000..6f96d73 --- /dev/null +++ b/lib/DBIx/Class/Manual/Features.pod @@ -0,0 +1,665 @@ +=head1 NAME + +DBIx::Class::Manual::Features - A boatload of DBIx::Class features with links to respective documentation + +=head1 META + +=head2 Large Community + +Currently there are 88 people listed as contributors to DBIC. That ranges +from documentation help, to test help, to added features, to entire database +support. + +=head2 Active Community + +Currently (June 9, 2010) 6 active branches (commited to +in the last two weeks) in git. Last release (0.08122) +had 14 new features, and 16 bug fixes. Of course that +L.) + +=head2 Responsive Community + +=over 1 + +=item I needed MSSQL order-by support; the community helped me add support + +=item generally very welcoming of people willing to help + +=back + +=head1 General ORM + +These are things that are in most other ORMs, but are still reasons to use +DBIC over raw SQL. + +=head2 Cross DB + +The vast majority of code should run on all databases without needing tweaking + +=head2 Basic CRUD + +=over 1 + +=item C - Create + +=item R - Retrieve + +=item U - Update + +=item D - Delete + +=back + +=head2 SQL: Create + + my $sth = $dbh->prepare(' + INSERT INTO books + (title, author_id) + values (?,?) + '); + + $sth->execute( 'A book title', $author_id ); + +=head2 DBIC: Create + + my $book = $book_rs->create({ + title => 'A book title', + author_id => $author_id, + }); + +See L + +=over 1 + +=item No need to pair placeholders and values + +=item Automatically gets autoincremented id for you + +=item Transparently uses INSERT ... RETURNING for databases that support it + +=back + +=head2 SQL: Read + + my $sth = $dbh->prepare(' + SELECT title, + authors.name as author_name + FROM books, authors + WHERE books.author = authors.id + '); + + while ( my $book = $sth->fetchrow_hashref ) { + say "Author of $book->{title} is $book->{author_name}"; + } + +=head2 DBIC: Read + + my $book = $book_rs->find($book_id); + +or + + my $book = $book_rs->search({ title => 'A book title' }, { rows => 1 })->next; + +or + + my @books = $book_rs->search({ author => $author_id })->all; + +or + + while( my $book = $books_rs->next ) { + printf "Author of %s is %s\n", $book->title, $book->author->name; + } + +See L, L, L, and L + +B + +=head2 SQL: Update + + my $update = $dbh->prepare(' + UPDATE books + SET title = ? + WHERE id = ? + '); + + $update->execute( 'New title', $book_id ); + +=head2 DBIC: Update + + $book->update({ title => 'New title' }); + +See L + +Will not update unless value changes + +=head2 SQL: Delete + + my $delete = $dbh->prepare('DELETE FROM books WHERE id = ?'); + + $delete->execute($book_id); + +=head2 DBIC: Delete + + $book->delete + +See L + +=head2 SQL: Search + + my $sth = $dbh->prepare(' + SELECT title, + authors.name as author_name + FROM books + WHERE books.name LIKE "%monte cristo%" AND + books.topic = "jailbreak" + '); + +=head2 DBIC: Search + + my $book = $book_rs->search({ + 'me.name' => { -like => '%monte cristo%' }, + 'me.topic' => 'jailbreak', + })->next; + +=over 1 + +=item See L, L, and L + +=item (kinda) introspectible + +=item Prettier than SQL + +=back + +=head2 OO Overidability + +=over 1 + +=item Override new if you want to do validation + +=item Override delete if you want to disable deletion + +=item and on and on + +=back + +=head2 Convenience Methods + +=over 1 + +=item L + +=item L + +=back + +=head2 Non-column methods + +Need a method to get a user's gravatar URL? Add a C method to the +Result class + +=head2 RELATIONSHIPS + +=over 1 + +=item L + +=item L + +=item L + +=item L + +=item L + +=item SET AND FORGET + +=back + +=head1 DBIx::Class Specific Features + +These things may be in other ORM's, but they are very specific, so doubtful + +=head2 ->deploy + +Create a database from your DBIx::Class schema. + + my $schema = Frew::Schema->connect( $dsn, $user, $pass ); + + $schema->deploy + +See L. + +See also: L + +=head2 Schema::Loader + +Create a DBIx::Class schema from your database. + + package Frew::Schema; + + use strict; + use warnings; + + use base 'DBIx::Class::Schema::Loader'; + + __PACKAGE__->loader_options({ + naming => 'v7', + debug => $ENV{DBIC_TRACE}, + }); + + 1; + + # elsewhere... + + my $schema = Frew::Schema->connect( $dsn, $user, $pass ); + +See L and L. + +=head2 Populate + +Made for inserting lots of rows very quicky into database + + $schema->populate([ Users => + [qw( username password )], + [qw( frew >=4char$ )], + [qw( ... )], + [qw( ... )], + ); + +See L + +I use populate L to export our whole +(200M~) db to SQLite + +=head2 Multicreate + +Create an object and it's related objects all at once + + $schema->resultset('Author')->create({ + name => 'Stephen King', + books => [{ title => 'The Dark Tower' }], + address => { + street => '123 Turtle Back Lane', + state => { abbreviation => 'ME' }, + city => { name => 'Lowell' }, + }, + }); + +See L + +=over 1 + +=item books is a has_many + +=item address is a belongs_to which in turn belongs to state and city each + +=item for this to work right state and city must mark abbreviation and name as unique + +=back + +=head2 Extensible + +DBIx::Class helped pioneer fast MI in Perl 5 with Class::C3, so it is made to +allow extensions to nearly every part of it. + +=head2 Extensibility example: DBIx::Class::Helpers + +=over 1 + +=item L + +=item L + +=item L + +=item L + +=item L + +=item L + +=item L + +=item L + +=item L + +=back + +=head2 Extensibility example: DBIx::Class::TimeStamp + +=over 1 + +=item See L + +=item Cross DB + +=item set_on_create + +=item set_on_update + +=back + +=head2 Extensibility example: Kioku + +=over 1 + +=item See L + +=item Kioku is the new hotness + +=item Mix RDBMS with Object DB + +=back + +=head2 Result vs ResultSet + +=over 1 + +=item Result == Row + +=item ResultSet == Query Plan + +=over 1 + +=item Internal Join Optimizer for all DB's (!!!) + +=back + +=item (less important but...) + +=item ResultSource == Queryable collection of rows (Table, View, etc) + +=item Storage == Database + +=item Schema == associates a set of ResultSources with a Storage + +=back + +=head2 ResultSet methods + + package MyApp::Schema::ResultSet::Book; + + use strict; + use warnings; + + use base 'DBIx::Class::ResultSet'; + + sub good { + my $self = shift; + $self->search({ + $self->current_source_alias . '.rating' => { '>=' => 4 } + }) + }; + + sub cheap { + my $self = shift; + $self->search({ + $self->current_source_alias . '.price' => { '<=' => 5} + }) + }; + + # ... + + 1; + +See L + +=over 1 + +=item All searches should be ResultSet methods + +=item Name has obvious meaning + +=item L helps things to work no matter what + +=back + +=head2 ResultSet method in Action + + $schema->resultset('Book')->good + +=head2 ResultSet Chaining + + $schema->resultset('Book') + ->good + ->cheap + ->recent + +=head2 search_related + + my $score = $schema->resultset('User') + ->search({'me.userid' => 'frew'}) + ->related_resultset('access') + ->related_resultset('mgmt') + ->related_resultset('orders') + ->telephone + ->search_related( shops => { + 'shops.datecompleted' => { + -between => ['2009-10-01','2009-10-08'] + } + })->completed + ->related_resultset('rpt_score') + ->search(undef, { rows => 1}) + ->get_column('raw_scores') + ->next; + +The SQL that this produces (with placeholders filled in for clarity's sake) +on our system (Microsoft SQL) is: + + SELECT raw_scores + FROM ( + SELECT raw_scores, ROW_NUMBER() OVER ( + ORDER BY ( + SELECT (1) + ) + ) AS rno__row__index + FROM ( + SELECT rpt_score.raw_scores + FROM users me + JOIN access access + ON access.userid = me.userid + JOIN mgmt mgmt + ON mgmt.mgmtid = access.mgmtid + JOIN [order] orders + ON orders.mgmtid = mgmt.mgmtid + JOIN shop shops + ON shops.orderno = orders.orderno + JOIN rpt_scores rpt_score + ON rpt_score.shopno = shops.shopno + WHERE ( + datecompleted IS NOT NULL AND + ( + (shops.datecompleted BETWEEN '2009-10-01' AND '2009-10-08') AND + (type = '1' AND me.userid = 'frew') + ) + ) + ) rpt_score + ) rpt_score + WHERE rno__row__index BETWEEN 1 AND 1 + +See: L, L, and L. + +=head2 bonus rel methods + + my $book = $author->create_related( + books => { + title => 'Another Discworld book', + } + ); + + my $book2 = $pratchett->add_to_books({ + title => 'MOAR Discworld book', + }); + +See L and L + +Note that it automaticaly fills in foreign key for you + +=head2 Excellent Transaction Support + + $schema->txn_do(sub { + ... + }); + + $schema->txn_begin; # <-- low level + # ... + $schema->txn_commit; + +See L, L, +and L. + +=head2 InflateColumn + + package Frew::Schema::Result::Book; + + use strict; + use warnings; + + use base 'DBIx::Class::Core'; + + use DateTime::Format::MySQL; + + # Result code here + + __PACKAGE__->load_components('InflateColumn'); + + __PACKAGE__->inflate_column( + date_published => { + inflate => sub { DateTime::Format::MySQL->parse_date( shift ) }, + deflate => sub { shift->ymd }, + }, + ); + +See L, L, and +L. + +=head2 InflateColumn: deflation + + $book->date_published(DateTime->now); + $book->update; + +=head2 InflateColumn: inflation + + say $book->date_published->month_abbr; # Nov + +=head2 FilterColumn + + package Frew::Schema::Result::Book; + + use strict; + use warnings; + + use base 'DBIx::Class::Core'; + + # Result code here + + __PACKAGE__->load_components('FilterColumn'); + + __PACKAGE__->filter_column( + length => { + to_storage => 'to_metric', + from_storage => 'to_imperial', + }, + ); + + sub to_metric { $_[1] * .305 } + sub to_imperial { $_[1] * 3.28 } + +See L and L + +=head2 ResultSetColumn + + my $rsc = $schema->resultset('Book')->get_column('price'); + $rsc->first; + $rsc->all; + $rsc->min; + $rsc->max; + $rsc->sum; + +See L + +=head2 Aggregates + + my @res = $rs->search(undef, { + select => [ + 'price', + 'genre', + { max => price }, + { avg => price }, + ], + as => [ + qw(price genre max_price avg_price) + ], + group_by => [qw(price genre)], + }); + for (@res) { + say $_->price . ' ' . $_->genre; + say $_->get_column('max_price'); + say $_->get_column('min_price'); + } + +See L, L, and +L + +=over 1 + +=item Careful, get_column can basicaly mean B things + +=item private in which case you should use an accessor + +=item public for what there is no accessor for + +=item public for get resultset column (prev example) + +=back + +=head2 HRI + + $rs->search(undef, { + result_class => 'DBIx::Class::ResultClass::HashRefInflator', + }); + +See L and L. + +=over 1 + +=item Easy on memory + +=item Mega fast + +=item Great for quick debugging + +=item Great for performance tuning (we went from 2m to < 3s) + +=back + +=head2 Subquery Support + + my $inner_query = $schema->resultset('Artist') + ->search({ + name => [ 'Billy Joel', 'Brittany Spears' ], + })->get_column('id')->as_query; + + my $rs = $schema->resultset('CD')->search({ + artist_id => { -in => $inner_query }, + }); + +See L + +=head2 Bare SQL w/ Placeholders + + $rs->update({ + # !!! SQL INJECTION VECTOR + price => \"price + $inc", # DON'T DO THIS + }); + +Better: + + $rs->update({ + price => \['price + ?', [inc => $inc]], + }); + +See L +