First, the simple stuff...
 
 
- After calling prepare() on a statement with placeholders:
- 
$sth = $dbh->prepare(“select * from table where k1=? and k2=?”);
 
 
- Values need to be assigned (‘bound’) to each placeholder before the database can execute the statement
- Either at execute, for simple cases:
- or before execute:
- 
$sth->bind_param(1, $p1);
 
 $sth->bind_param(2, $p2);
 $sth->execute;