SELECT FRIDAYS between 2 dates

SELECT * FROM (select * from 
(select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 + t0.i) selected_date from
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t3,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t4) v
where selected_date between '2012-01-1' and '2012-05-15')x WHERE DATE_FORMAT( x.selected_date , '%w' ) = 5 

SQL for permuation and combination

SELECT (
t4.i *10000 + t3.i *1000 + t2.i *100 + t1.i *10 + t0.i
)selected_date
FROM (
SELECT 0 i
UNION SELECT 1 
UNION SELECT 2
)t0, (
SELECT 0 i
UNION SELECT 1 
UNION SELECT 2
)t1, (
SELECT 0 i
UNION SELECT 1 
UNION SELECT 2
)t2, (
SELECT 0 i
UNION SELECT 1 
UNION SELECT 2
)t3, (
SELECT 0 i
UNION SELECT 1 
UNION SELECT 2
)t4