Join Union ...grouping records

[gauravpth]

Hi,
I basically have three tables from which i need to fetch the data which i am doing using inner joins and its working fine...
But now the problem is that i need to group the resultant data using column in one of the table satisfying certain conditions i.e
I have something like this :

SELECT first_table.field1, first_table.field2, second_table.field3, second_table.field4, third_table.field5, third_table.field6
FROM first_table
INNER JOIN second_table
ON first_table.keyfield = second_table.foreign_keyfield
INNER JOIN third_table
ON second_table.keyfield = third_table.foreign_keyfield

But now i want to further group the resultant records into different groups depending upon something like :
where third_table.field5 in (' val1', ' val2')
where third_table.field5 in (' val3', ' val4')
where third_table.field5 in (' val5', ' val6')

Can anyone Please help me with this second part...

[PAVB]

Please take the following as untested pseudo-code under the assumption you are trying to do a group by

select  ..., 
        decode(third_table.field5,val1,1,val2,1,val3,2,val4,2,val5,3,val6,3) "MYGROUP"
from
(
SELECT first_table.field1, first_table.field2, second_table.field3, second_table.field4, third_table.field5, third_table.field6
FROM first_table
INNER JOIN second_table
ON first_table.keyfield = second_table.foreign_keyfield
INNER JOIN third_table
ON second_table.keyfield = third_table.foreign_keyfield
)
group by "MYGROUP"
;