Long time SQL user of many flavors but brand new to PL/SQL and struggling to learn the "Oracle way". I've seen MANY examples of using variables in queries online and in documentation, but I've been unsuccessful finding a sample of what I want to do and how to do it.

I've written the logic to calculate a date that is a variable number of business days before a given date - took a while (not from the logic perspective but from the "Oracle way" perspective again) but I figured that out and have that date sitting in a variable after the calculation. Now I want to use that date in the WHERE clause of a SELECT statement to pull all rows >= the variable date. All the examples I see are for singleton row returns, i.e. id = <variable> which returns one row, I need ALL rows returned in the result set and displayed/output.

How do I do this in Oracle? I have the query in SQL Developer but ultimately trying to replace this:

AND vod_ins_Date >= TRUNC(sysdate-10)

With

AND vod_ins_Date >= TRUNC(<VARIABLE_VALUE_HERE>)

and have it return all appropriate rows (more than 1).

create table t (
  c1 date
);

insert into t 
  with rws as (
    select date'2018-09-30' + level c1 from dual
    connect by level <= 10
  )
    select c1 from rws;
commit;

var dt varchar2(10);

exec :dt := '2018-10-07';

select * from t
where  c1 >= to_date ( :dt, 'YYYY-MM-DD' );

C1                     
07-OCT-2018 00:00:00   
08-OCT-2018 00:00:00   
09-OCT-2018 00:00:00   
10-OCT-2018 00:00:00  

declare
  dt date := date'2018-10-07';
begin
  for rws in ( 
    select * from t
    where  c1 >= dt
  ) loop
    dbms_output.put_line ( to_char ( rws.c1, 'YYYY-MM-DD' ) );
  end loop;
end;
/

2018-10-07
2018-10-08
2018-10-09
2018-10-10