How to tell if value in database is 0 or null when the value in ResultSet is 0?

For example, you have a count column in your sales table. When you query the table,

      String sql = "select itemId, count from sales where employeeId = 950780";
      PreparedStatement ps = conn.prepareStatement(sql);
      ResultSet rs = ps.executeQuery();
      while (rs.next()) {
            System.out.println("Item: " + rs.getString("itemId") + ", Count: "+rs.getInt("count"));
      }

When the count is null in the database, it returns 0 by rs.getInt("count"). How could you tell if the count is 0 or null? The ResultSet wasNull() method will give you the answer.

     int count = rs.getInt("count"); //After this immediately call the wasNull method.
     boolean isNull = rs.wasNull();

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