4 use vars qw($DEBUG $buffer);
6 use FS::UID qw(myconnect);
7 use Scalar::Util qw(refaddr);
11 # this might become a parameter at some point, but right now, you can
12 # "local $FS::Cursor::buffer = X;"
17 FS::Cursor - Iterator for querying large data sets
23 my $search = FS::Cursor->new('table', { field => 'value' ... });
24 while ( my $row = $search->fetch ) {
34 Constructs a cursored search. Accepts all the same arguments as qsearch,
35 and returns an FS::Cursor object to fetch the rows one at a time.
41 my $q = FS::Record::_query(@_); # builds the statement and parameter list
42 my $dbh = myconnect();
46 class => 'FS::' . ($q->{table} || 'Record'),
52 # the class of record object to return
53 $self->{class} = "FS::".($q->{table} || 'Record');
55 # save for later, so forked children will not destroy me when they exit
58 $self->{id} = sprintf('cursor%08x', refaddr($self));
59 my $statement = "DECLARE ".$self->{id}." CURSOR FOR ".$q->{statement};
61 my $sth = $dbh->prepare($statement)
64 foreach my $value ( @{ $q->{value} } ) {
65 my $bind_type = shift @{ $q->{bind_type} };
66 $sth->bind_param($bind++, $value, $bind_type );
69 $sth->execute or die $sth->errstr;
71 $self->{fetch} = $dbh->prepare("FETCH FORWARD $buffer FROM ".$self->{id});
84 Fetch the next row from the search results.
89 # might be a little more efficient to do a FETCH NEXT 1000 or something
90 # and buffer them locally, but the semantics are simpler this way
92 if (@{ $self->{buffer} } == 0) {
93 my $rows = $self->refill;
94 return undef if !$rows;
96 $self->{class}->new(shift @{ $self->{buffer} });
101 my $sth = $self->{fetch};
102 $sth->execute or die $sth->errstr;
103 my $result = $self->{fetch}->fetchall_arrayref( {} );
104 $self->{buffer} = $result;
110 return unless $self->{pid} eq $$;
111 $self->{dbh}->do('CLOSE '. $self->{id})
112 or die $self->{dbh}->errstr; # clean-up the cursor in Pg
113 $self->{dbh}->rollback;
114 $self->{dbh}->disconnect;
121 Replace all uses of qsearch with this.
125 Doesn't support MySQL.
127 The cursor will close prematurely if any code issues a rollback/commit. If
128 you need protection against this use qsearch or fork and get a new dbh
130 Normally this issue will represent itself this message.
131 ERROR: cursor "cursorXXXXXXX" does not exist.