Select from many tables of the same type

Question

Hi everybody!
My problem is the next:
I have many tables with big account of data (millions regs), so I did something like that:
The regs dated 1999 are in the table XXX_1999, those dated 2000 - in XXX_2000, and so on.
Now, if I want to make query from date1 to date2 (could be some years of difference), I don't know the number of tables I have to query in execution time.
I want to make a procedure that returns 1 recordset (or cursor) with all the data in it without using temporary tables.
Is it possible and how?
Thanks

Answer 1

SQL> r
  1  declare
  2    c_CRLF constant varchar2(2) := chr(13)||chr(10);
  3
  4    v_date1 date := to_date('15.03.2001', 'DD.MM.YYYY');
  5    v_date2 date := to_date('17.08.2003', 'DD.MM.YYYY');
  6
  7    cursor c_years is
  8      select to_number(to_char(v_date1, 'YYYY')) + rownum-1 year
  9      from user_tables
10      where rownum <= to_number(to_char(v_date2, 'YYYY')) -to_number(to_char(v_date1, 'YYYY')) +1;
11
12    v_stmnt varchar2(2000);
13  begin
14    for rec in c_years loop
15      if c_years%ROWCOUNT > 1 then
16        v_stmnt := v_stmnt || c_CRLF ||'UNION ALL' || c_CRLF;
17      end if;
18      v_stmnt := v_stmnt || 'select * from XXX_'||rec.year;
19    end loop;
20    dbms_output.put_line(v_stmnt);
21* end;
select * from XXX_2001
UNION ALL
select * from XXX_2002
UNION ALL
select * from XXX_2003
PL/SQL procedure successfully completed.
SQL>You will need to add some bounds checking to avoid "table or view does not exist'
if date1 < 2001 -> date1=2001
if date2 > current year -> date2=current year
Message was edited by:
Jens Petersen