title: Can anyone explain :: meaning in postgresql?
body: <p>I have below query which works properly but don't know meaning and use of <code>::</code> in postgresql.</p>
  
  <pre><code>select (
      select ( 
          case when 1 &gt; 0 then 1::float / (
              select count(id) from transactions_products where transaction_id in (
              select id from transactions_transactions tt 
              where status = 3 and fi = 355 
                  and (invoice_date &gt;= 1420754400) 
                  and (invoice_date &lt;= 1421099999) 
                  and (tt.division_id = 107) 
                  and (tt.department_id = 210) 
          ) and is_vehicle = 1 
      )::float else 0 end)
   limit 1) as f_4
  </code></pre>