Question

I am currently getting this output from my query:-

Count(Total)| Type1
-----------------
 24            T1

  22           T2

But I want the output like this:-

 T1   T2
----------
 24   22

Note that Type1 column can contain any values like T1,T2,T3 so I cannot fix the values in the query. I am using Oracle 10g, how can I do it?

Answer 1

Oracle 10g does not have a PIVOT function so you can use an aggregate with a CASE:

select 
  sum(case when type1 = 'T1' then total end) T1,
  sum(case when type1 = 'T2' then total end) T2
from <yourquery goes here>

See SQL Fiddle with Demo

Or you can implement this directly into a query similar to this, using the SUM() aggregate will count each occurrence that matches the type1 value in the CASE statement:

select 
  sum(case when type1 = 'T1' then 1 else 0 end) T1,
  sum(case when type1 = 'T2' then 1 else 0 end) T2
from yourtable

If you have an unknown number of values to transform into columns, then you will want to use a procedure similar to this:

CREATE OR REPLACE procedure dynamic_pivot(p_cursor in out sys_refcursor)
as
    sql_query varchar2(1000) := 'select ';

    begin
        for x in (select distinct type1 from yourtable order by 1)
        loop
            sql_query := sql_query ||
              ' , sum(case when type1 = '''||x.type1||''' then 1 else 0 end) as '||x.type1;

                dbms_output.put_line(sql_query);
        end loop;

        sql_query := sql_query || ' from yourtable';

        open p_cursor for sql_query;
    end;
/

Then to execute it:

variable x refcursor
exec dynamic_pivot(:x)
print x