DBI bind_param 怎样绑定bit类型

l1183479157

my $dbh=DBI->connect("DBI:mysql:database=***;host=localhost","root","1234");
my $sql="insert into grcw_yslx(name,parentid,flag) values(?,?,?)";
$dbh->do("SET NAMES 'utf8'");
my $sth=$dbh->prepare($sql);
$sth->bind_param(1,'****');
$sth->bind_param(2,-1);
$sth->bind_param(3,3,SQL_BIT);
执行sql时报错，有没有人知道怎样绑定一个bit类型的数据