Table of Contents for

MySQL in a Nutshell, 2nd Edition

This function associates or binds a value in an SQL statement to a placeholder. Placeholders are indicated by ? in SQL statements and are numbered in the order they appear in the statement, starting with 1. The first argument indicates which placeholder to replace with a given value, i.e., the second argument. The data type may be specified as a third argument. Here is an example:

...
my $sql_stmnt = "SELECT title, publisher
                 FROM books WHERE author = ?
                 AND status = ?";
my $sth = $dbh->prepare($sql_stmnt);
$sth->bind_param(1, $author);
$sth->bind_param(2, $status);
$sth->execute();
while(my ($title,$publisher) = $sth->fetchrow_array()) {
   print "$title ($publisher) \n";
}

In this example, a placeholder (a question mark) is given in the SQL statement and is replaced with the actual value of $author using bind_param(). This must be done before the execute() is issued.