SQL & PL/SQL

Dear All,

I have a table with 2 rows and one has varchar type data and the other is the time stamp (04/02/2013 19:44:40).

Now I want to write a query to count number of rows per hour in the table with date ...strcutre is as follows :


ddata varchar2(20)
ddate date with timestamp ;

Require the output as follows :

March 28th 12 AM - 20
March 28th 1 AM - 40
March 28th 2 AM - 40

where March 28th 12 AM is the date with time
and 20 - number of rows in that date and in that hour..

Please advise..