=head1 NAME
DBIx::SQLEngine::Driver::Pg - Support DBD::Pg
=head1 SYNOPSIS
B<DBI Wrapper>: Adds methods to a DBI database handle.
my $sqldb = DBIx::SQLEngine->new( 'dbi:pg:test' );
B<Portability Subclasses:> Uses driver's idioms or emulation.
$hash_ary = $sqldb->fetch_select(
table => 'students'
limit => 5, offset => 10
);
=head1 DESCRIPTION
This package provides a subclass of DBIx::SQLEngine which compensates for Postgres's idiosyncrasies.
=head2 About Driver Subclasses
You do not need to use this package directly; when you connect to a database, the SQLEngine object is automatically re-blessed in to the appropriate subclass.
=cut
########################################################################
package DBIx::SQLEngine::Driver::Pg;
use strict;
use Carp;
########################################################################
=head2 sql_limit
$sqldb->sql_limit( $limit, $offset, $sql, @params ) : $sql, @params
Adds support for SQL select limit clause.
=cut
sub sql_limit {
my $self = shift;
my ( $limit, $offset, $sql, @params ) = @_;
# You can't apply "limit" to non-table fetches like "select LAST_INSERT_ID"
if ( $sql =~ /\bfrom\b/i and defined $limit or defined $offset) {
$sql .= " limit $limit" if $limit;
$sql .= " offset $offset" if $offset;
}
return ($sql, @params);
}
########################################################################
=head2 do_insert_with_sequence
$sqldb->do_insert_with_sequence( $sequence_name, %sql_clauses ) : $row_count
Implemented using _seq_do_insert_preinc and seq_increment.
=head2 seq_increment
$sqldb->seq_increment( $table, $field ) : $new_value
Increments the sequence, and returns the newly allocated value.
=cut
# $rows = $self->do_insert_with_sequence( $sequence, %clauses );
sub do_insert_with_sequence {
(shift)->_seq_do_insert_preinc( @_ )
}
# $current_id = $sqldb->seq_increment( $table, $field );
sub seq_increment {
my ($self, $table, $field) = @_;
$self->fetch_one_value(
sql => "SELECT nextval('${table}_${field}_seq')"
);
}
########################################################################
=head2 dbms_create_column_types
$sqldb->dbms_create_column_types () : %column_type_codes
Implemented using Pg's bytea and serial types.
=head2 dbms_create_column_text_long_type
$sqldb->dbms_create_column_text_long_type () : $col_type_str
Implemented using Pg's text type.
=cut
sub dbms_create_column_types {
'sequential' => 'serial',
'binary' => 'bytea',
}
sub dbms_create_column_text_long_type {
'text'
}
########################################################################
=head2 recoverable_query_exceptions
$sqldb->recoverable_query_exceptions() : @common_error_messages
Provides a list of error messages which represent common
communication failures or other incidental errors.
=cut
sub recoverable_query_exceptions {
'backend closed the channel unexpectedly',
'there is no connection to the backend',
'reconnect to the database system and repeat your query',
'no statement executing',
'fetch without execute',
'field number \d+ is out of range 0\.\.\-1',
}
########################################################################
=head1 SEE ALSO
See L<DBIx::SQLEngine> for the overall interface and developer documentation.
See L<DBIx::SQLEngine::Docs::ReadMe> for general information about
this distribution, including installation and license information.
=cut
########################################################################
1;