Group by month of the date

Question

I need to generate a report based on the month of a date field.its look like
month arrived patients
May 100
june 129
July 154
How can i write the group by select command on the field of a date. Kindly help me.

Answer 1

SQL> create table mytable (arrival_date,patient)
  2  as
  3  select date '2007-05-10', 'Bob' from dual union all
  4  select date '2007-06-05', 'Mary' from dual union all
  5  select date '2007-06-20', 'Phil' from dual union all
  6  select date '2007-06-25', 'George' from dual union all
  7  select date '2007-07-10', 'Sue' from dual union all
  8  select date '2007-07-15', 'Mike' from dual
  9  /
Tabel is aangemaakt.
SQL> select trunc(arrival_date,'mm') month
  2       , count(*) arrived_patients
  3    from mytable
  4   group by trunc(arrival_date,'mm')
  5  /
MONTH                                     ARRIVED_PATIENTS
01-05-2007 00:00:00                                      1
01-06-2007 00:00:00                                      3
01-07-2007 00:00:00                                      2
3 rijen zijn geselecteerd.or formatting the first column:
SQL> select to_char(trunc(arrival_date,'mm'),'month','nls_date_language=american') month
  2       , count(*) arrived_patients
  3    from mytable
  4   group by trunc(arrival_date,'mm')
  5  /
MONTH                           ARRIVED_PATIENTS
may                                            1
june                                           3
july                                           2
3 rijen zijn geselecteerd.Regards,
Rob.