disabled 10 :ˆl—äY>” ªe¶¥8 ]¸Û—uLZ7ÿ ƒh¹a–äY>” ªe¶¥8 _¸Ë7Ú˜´oÁ10 #ˆl–ß=¿J¥!®Å² …p.Ü êbÑ¿Ä „}ï¿Â?÷=head1 NAME DBD::File::Developers - Developers documentation for DBD::File =head1 SYNOPSIS package DBD::myDriver; use base qw( DBD::File ); sub driver { ... my $drh = $proto->SUPER::driver ($attr); ... return $drh->{class}; } sub CLONE { ... } package DBD::myDriver::dr; @ISA = qw( DBD::File::dr ); sub data_sources { ... } ... package DBD::myDriver::db; @ISA = qw( DBD::File::db ); sub init_valid_attributes { ... } sub init_default_attributes { ... } sub set_versions { ... } sub validate_STORE_attr { my ($dbh, $attrib, $value) = @_; ... } sub validate_FETCH_attr { my ($dbh, $attrib) = @_; ... } sub get_myd_versions { ... } package DBD::myDriver::st; @ISA = qw( DBD::File::st ); sub FETCH { ... } sub STORE { ... } package DBD::myDriver::Statement; @ISA = qw( DBD::File::Statement ); package DBD::myDriver::Table; @ISA = qw( DBD::File::Table ); my %reset_on_modify = ( myd_abc => "myd_foo", myd_mno => "myd_bar", ); __PACKAGE__->register_reset_on_modify (\%reset_on_modify); my %compat_map = ( abc => 'foo_abc', xyz => 'foo_xyz', ); __PACKAGE__->register_compat_map (\%compat_map); sub bootstrap_table_meta { ... } sub init_table_meta { ... } sub table_meta_attr_changed { ... } sub open_data { ... } sub fetch_row { ... } sub push_row { ... } sub push_names { ... } # optimize the SQL engine by add one or more of sub update_current_row { ... } # or sub update_specific_row { ... } # or sub update_one_row { ... } # or sub insert_new_row { ... } # or sub delete_current_row { ... } # or sub delete_one_row { ... } =head1 DESCRIPTION This document describes how DBD developers can write DBD::File based DBI drivers. It supplements L and L, which you should read first. =head1 CLASSES Each DBI driver must provide a package global C method and three DBI related classes: =over 4 =item DBD::File::dr Driver package, contains the methods DBI calls indirectly via DBI interface: DBI->connect ('DBI:DBM:', undef, undef, {}) # invokes package DBD::DBM::dr; @DBD::DBM::dr::ISA = qw( DBD::File::dr ); sub connect ($$;$$$) { ... } Similar for C<< data_sources >> and C<< disconnect_all >>. Pure Perl DBI drivers derived from DBD::File do not usually need to override any of the methods provided through the DBD::XXX::dr package however if you need additional initialization in the connect method you may need to. =item DBD::File::db Contains the methods which are called through DBI database handles (C<< $dbh >>). e.g., $sth = $dbh->prepare ("select * from foo"); # returns the f_encoding setting for table foo $dbh->csv_get_meta ("foo", "f_encoding"); DBD::File provides the typical methods required here. Developers who write DBI drivers based on DBD::File need to override the methods C<< set_versions >> and C<< init_valid_attributes >>. =item DBD::File::st Contains the methods to deal with prepared statement handles. e.g., $sth->execute () or die $sth->errstr; =back =head2 DBD::File This is the main package containing the routines to initialize DBD::File based DBI drivers. Primarily the C<< DBD::File::driver >> method is invoked, either directly from DBI when the driver is initialized or from the derived class. package DBD::DBM; use base qw( DBD::File ); sub driver { my ($class, $attr) = @_; ... my $drh = $class->SUPER::driver ($attr); ... return $drh; } It is not necessary to implement your own driver method as long as additional initialization (e.g. installing more private driver methods) is not required. You do not need to call C<< setup_driver >> as DBD::File takes care of it. =head2 DBD::File::dr