historical (immutable) invoice details about services and other history infrastructure

[freeside.git] / FS / FS / h_Common.pm

diff --git a/FS/FS/h_Common.pm b/FS/FS/h_Common.pm
new file mode 100644 (file)
index 0000000..58ead88
--- /dev/null
+++ b/FS/FS/h_Common.pm
@@ -0,0 +1,83 @@
+package FS::h_Common;
+
+use strict;
+use FS::Record qw(dbdef);
+
+=head1 NAME
+
+FS::h_Common - History table "mixin" common base class
+
+=head1 SYNOPSIS
+
+package FS::h_tablename;
+@ISA = qw( FS::h_Common FS::tablename ); 
+
+sub table { 'h_table_name'; }
+
+sub insert { return "can't insert history records manually"; }
+sub delete { return "can't delete history records"; }
+sub replace { return "can't modify history records"; }
+
+=head1 DESCRIPTION
+
+FS::h_Common is intended as a "mixin" base class for history table classes to
+inherit from.
+
+=head1 METHODS
+
+=over 4
+
+=item sql_h_search END_TIMESTAMP [ START_TIMESTAMP ] 
+
+Returns an a list consisting of the "SELECT" and "EXTRA_SQL" SQL fragments to
+search for the appropriate history records created before END_TIMESTAMP
+and (optionally) not cancelled before START_TIMESTAMP.
+
+=cut
+
+sub sql_h_search {
+  my( $self, $end ) = ( shift, shift );
+
+  my $table = $self->table;
+  my $pkey = dbdef->table($table)->primary_key
+    or die "can't (yet) search history table $table without a primary key";
+
+  my $notcancelled = '';
+  if ( scalar(@_) && $_[0] ) {
+    $notcancelled = "AND 0 = ( SELECT COUNT(*) FROM $table as notdel
+                                WHERE notdel.$pkey = maintable.$pkey
+                                AND notdel.history_action = 'delete'
+                                AND notdel.history_date > maintable.history_date
+                                AND notdel.history_date <= $_[0]
+                             )";
+  }
+
+  (
+    "DISTINCT ON ( $pkey ) *",
+
+    "AND history_date <= $end
+     AND (    history_action = 'insert'
+           OR history_action = 'replace_new'
+         )
+     $notcancelled
+     ORDER BY $pkey ASC, history_date DESC",
+
+     '',
+
+     'maintable',
+  );
+
+}
+
+=back
+
+=head1 BUGS
+
+=head1 SEE ALSO
+
+L<FS::Record>, schema.html from the base documentation
+
+=cut
+
+1;
+