sub build_sql () {
my $table = shift;
my %where = @_; # should use hash refs, but this is an example
my $sql = "select * from $table where ";
 foreach (keys(%where)) {
  #assumes quote() defined elsewhere to escape values
  $sql .= "$_ = ".quote($where{$_}).',';
 }
 chop $sql; #remove trailing comma 
 return $sql
}