hello Beter,
you can’t use SQL Statement directly in a PL/SQL expression instead you can use variable to store your count then use your variable into PL/SQL expression like this :

DECLARE
  v_count   NUMBER;
BEGIN
  SELECT count (*) INTO v_count FROM dual;

  IF v_count >= 1 THEN
    dbms_output.put_line ('true');
  ELSE
    dbms_output.put_line ('false');
  END IF;
END;

or as you mentioned if you want to use it inside delete statement like this :

DELETE FROM table_1
WHERE       (SELECT count (*) FROM table_2) >= 1;

hope this helpful 🙂

first thing data must be saved as extension .CSV not .xls
second we need to create directory and give (EXECUTE, READ, WRITE) privilege to appropriate user which will use this directory later into procedure we will create
create directory syntax

CREATE OR REPLACE DIRECTORY 
TEMP_DIR AS 
'C:temp';
GRANT EXECUTE, READ, WRITE ON DIRECTORY TEMP_DIR TO USER WITH GRANT OPTION;

Note : “C:temp” this statement to create directory on windows server it will be little deference from Linux server.
third thing you need to create stage table which we will insert data into it by mapping excel column to be the same with columns name :

CREATE TABLE DOCARCH.TEST
(
  TYPE_ID       NUMBER
)

and now it’s time to read the data inside csv file and inserted to stage table by this procedure

create or replace procedure imp_proc_test
is
  file_handle   utl_file.file_type := UTL_FILE.FOPEN('TEMP_DIR','imptestdata.csv','R',5000);
  var1          test.TYPE_ID%type;
  v_string      varchar2 (1000);
begin
    loop
        begin
        UTL_FILE.get_line(file_handle,v_string);
        var1 := substr(v_string,1,instr(v_string,',',1,1)-1);
        insert into test (TYPE_ID) values (var1);
        exception
          when no_data_found then
              UTL_FILE.fclose (file_handle);
              exit;
           WHEN OTHERS THEN
             DBMS_OUTPUT.PUT_LINE(sqlcode||sqlerrm);
        end;
    end loop;
    commit;
end;

so now after created this procedure just call it by :

exec imp_proc_test

at the final there is too many ways to achieve this requirement but we pick easiest one for you so please if you have any addition just share with others here.