title: Can this SQL be generated use Fey::SQL?
body: <p>I want to generate SQL like this:</p>
  
  <pre><code>SELECT coalesce(max(a.a_index) + 1, 0) as a_index FROM table1 a
  </code></pre>
  
  <p>I can get everything but the "+ 1".  Is there a way to add this to the query?</p>
  
  <pre><code>use strict;
  
  use Fey::Schema;
  use Fey::Loader;
  
  use DBI;
  
  my $dbh = DBI-&gt;connect("DBI:mysql:....", "...", "...");
  
  my $loader = Fey::Loader-&gt;new( dbh =&gt; $dbh );
  
  my $s = $loader-&gt;make_schema();
  
  my $q = Fey::SQL-&gt;new_select();
  
  my $a_table = $s-&gt;table('table1')-&gt;alias('a');
  
  my $a_index_col = $a_table-&gt;column('a_index');
  
  my $max_a_index_func = Fey::Literal::Function-&gt;new('max', $a_index_col);
  $max_a_index_func-&gt;set_alias_name('max_a_index');
  
  my $c_a_index_func = Fey::Literal::Function-&gt;new('coalesce', $max_a_index_func, "0");
  $c_a_index_func-&gt;set_alias_name('a_index');
  
  $q-&gt;select($c_a_index_func);
  $q-&gt;from($a_table);
  
  print $q-&gt;sql($dbh);
  print "\n";
  </code></pre>
  
  <p>Output</p>
  
  <pre><code>SELECT coalesce(max(`a`.`a_index`), 0) AS `a_index` FROM `table1` AS `a`
  </code></pre>