Creating sql query using 3 tables

Question

There is database (supposed to be relational but it is not) and
I cannot change the tables and it is very difficult to create SQL query.
Please, help!
First table T1
a1 char 20
time timestamp
a2 char 7 (the same as t2.a2 when is trimmed)
a3 number 5,0
a4 number 8,4
a5 number 7,3
Second table T2
a2 char 15
b1 number 1,0
b2 char 1,0
b3 char 4
a3 number 5,0
Third table T3
b3 char 4
c1 char 4
c2 number 7,3
c3 number 8,4
So, I need to create query (is it possible at all!?) from those 3 tables (a1, a2, b1,b2,b3, a4, a5, c2,c3
where time is within interval (from, to), a3 in interval (1,2,3,4), t2.b3=t3.b3, t1.a2=t2.a2
group by or sorted by a1, then, a2.
Any suggestion is welcome!
Thanks!
By the way, I will use this query in Crystal Reports.

Answer 1

As I already mentioned, I received another conditions for the query, and when I create a new one, I
First table T1
a1 number 5,0
a2 char 7 (the same as t2.a2 when is trimmed)
a3 number 8,4
a4 number 7,3
a_time timestamp
Second table T2
a2 char 15
b1 number 1,0
b2 char 1,0
b3 char 4
b4 char 4
Third table T3
c1 char 4
c2 number 7,3
c3 number 8,4
b3 char 4
where if c1='MIN' c2, c3 return min values,
and if c1='MAX' c2,c3 return max values
SQL query:
select t1.a1, t1.a2, t2.b1, t2.b2, t2.b3, t1.a3, t1.a4, t3.c1,
t3.c2, t3.c3, t2.b4
from t1, t2, t3
where (TRIM(t1.a2)=TRIM(t2.a2)
and t1.a1=19
and ((to_char(t1.a_time, 'YYYY-MM-DD') >= '2006-03-15')
and (to_char(t1.a_time, 'YYYY-MM-DD') <= '2006-03-16')))
and t3.b3=t2.b3)
order by t1.a_time
Result set:
a1, a2, b1, b2, b3, a3, a4, c1('MAX'), c2', c3', b4
a1, a2, b1, b2, b3, a3, a4, c1('MIN'), c2", c3", b4
So when I executed SQL query it returns 2 rows for the same a2.
I want to get 1 row for each a2 together with c3 (c4) min and c3 (c4) max values.
How to name columns for c2 min and c2 max (the same for c3) in order to retreive 1 row per a2 value, something like this:
a1, a2, b1, b2, b3, a3, a4, c2min, c2max, c3min, c3max, b4
Thanks