Adding Ben Simpson's new persistence layer.

lib/WebGUI/Persistent/Query/Select.pm

@@ -0,0 +1,171 @@
+package WebGUI::Persistent::Query::Select;
+
+=head1 LEGAL
+
+ -------------------------------------------------------------------
+  WebGUI is Copyright 2001-2003 Plain Black LLC.
+ -------------------------------------------------------------------
+  Please read the legal notices (docs/legal.txt) and the license
+  (docs/license.txt) that came with this distribution before using
+  this software.
+ -------------------------------------------------------------------
+  http://www.plainblack.com                     info@plainblack.com
+ -------------------------------------------------------------------
+
+=cut
+
+
+use strict;
+use warnings;
+use WebGUI::Persistent::Query;
+
+=head1 NAME
+
+Package WebGUI::Persistent::Query::Select
+
+=head1 DESCRIPTION
+
+This class allows reliable dynamic building of Sql select queries.
+
+=head1 SYNOPSIS
+
+ my $query = WebGUI::Persistent::Query::Select->new(
+   where => [A => [1,2],[{C => 'hello',B => 1}]],
+   table => 'myTable',
+   limit => 1,
+   groupBy => 'D',
+   properties => {
+     A => { },
+     B => { },
+     C => { quote => 1 },
+     D => { quote => 1 },
+   }
+ );
+
+ $query->buildQuery();
+
+Returns:
+
+  SELECT A,B,C,D 
+  FROM myTable 
+  WHERE A IN (1,2) AND (C = 'hello' OR B = 1) LIMIT 1 GROUP BY D
+
+=cut
+
+our @ISA = qw(WebGUI::Persistent::Query);
+
+#-------------------------------------------------------------------
+
+sub buildFrom { "FROM ".$_[0]->{_table} }
+
+#-------------------------------------------------------------------
+
+sub buildGroupBy { 
+     my ($self) = @_;
+     return '' unless $self->{_groupBy} && @{$self->{_groupBy}};
+     return 'GROUP BY '.join(',',@{$self->{_groupBy}});
+}
+
+#-------------------------------------------------------------------
+
+sub buildLimit { $_[0]->{_limit} ? "LIMIT ".$_[0]->{_limit} : '' }
+
+#-------------------------------------------------------------------
+
+sub buildOrderBy { 
+     my ($self) = @_;
+     return '' unless $self->{_orderBy} && @{$self->{_orderBy}};
+     return 'ORDER BY '.join(',',@{$self->{_orderBy}});
+}
+
+#-------------------------------------------------------------------
+
+=head2 buildQuery
+
+=cut
+
+sub buildQuery {
+     my ($self) = @_;
+
+     my @clauses = ('SELECT',
+                    $self->buildSelectFields(),
+                    $self->buildFrom());
+
+     if (my $where = $self->buildWhere()) {
+          push @clauses,$where;
+     }
+     if (my $group_by = $self->buildGroupBy()) {
+          push @clauses,$group_by;
+     }
+     if (my $order_by = $self->buildOrderBy()) {
+          push @clauses,$order_by;
+     }
+     if (my $limit = $self->buildLimit()) {
+          push @clauses,$limit;
+     }
+     return join(' ',@clauses);
+}
+
+#-------------------------------------------------------------------
+
+sub buildSelectFields {
+     my ($self) = @_;
+     return join(', ',@{$self->{_fields}}) if @{$self->{_fields}};
+     return join(', ',keys %{$self->{_properties}}) if %{$self->{_properties}};
+     return '*';
+}
+
+#-------------------------------------------------------------------
+
+=head2 new( %p )
+
+=over
+
+=item fields
+
+An array reference of field names (optional).
+
+=item groupBy
+
+An array reference of fields to group results by
+
+=item limit
+
+A scalar limit.
+
+=item orderBy
+
+An array reference of fields to order results by
+
+=item properties
+
+=over
+
+=item * quote
+
+If true values for this field are automatically quoted.
+
+=back
+
+=item table
+
+The name of the table to query.
+
+=item where
+
+A hash reference or array reference of arguments to build a where clause from.
+See WebGUI::Persistent::Query::parseWhereArgs for details.
+
+=cut
+
+sub new {
+     my ($class,%p) = @_;
+     my $self = $class->SUPER::new(%p);
+     $self->{_fields} = $p{fields} || [];
+     $self->{_limit} = $p{limit};
+     $self->{_group_by} = $p{groupBy};
+     $self->{_order_by} = $p{orderBy};
+     return $self;
+}
+
+1;