Declare statement in PL/SQL for a part of the query

Question

I have a query like the following:

select t1.varid, t1.var1, t1.var2, t1.vardata, t2.varid, t2.var1, t2,.var2 
from   table1 t1, table2 t2
where  t1.varid = t2.varid
and    t1.vardata between to_date('20170807','YYYYMMDD') and to_date('20170808','YYYYMMDD')

Now the question is: I need to extract the data not only in the data range specified in the query above, but I want to extract many other ranges in the same query.

To do that, I used UNION ALL and it works. The problem is that I have to re-write this part many times:

select t1.varid, t1.var1, t1.var2, t1.vardata, t2.varid, t2.var1, t2, var2 
from   table1 t1, table2 t2
where  t1.varid = t2.varid

Is there a tip for how to define select t1.varid... as a named variable in order to avoid a long boring repeated query?

Any other solutions are welcome.

Answer 1

As discussed in the chat you can do it as below:

SELECT t1.varid  as col1,
       t1.var1   as col2,
       t1.var2,
       t1.vardata,
       t2.varid,
       t2.var1,
       t2,
       .var2
  FROM table1 t1, table2 t2
 WHERE     t1.varid = t2.varid
       AND t1.vardata BETWEEN TO_DATE ('20170807', 'YYYYMMDD')
                          AND TO_DATE ('20170808', 'YYYYMMDD')
        --- Give date ranges.                  
       OR   t1.vardata BETWEEN TO_DATE ('20170907', 'YYYYMMDD')
                          AND TO_DATE ('20171008', 'YYYYMMDD')                  
       OR ....
       OR ....