create or replace procedure pt is
l_count integer:=0;
v_sid varchar2(1000);
begin
SELECT name
   INTO v_sid
   FROM v$database;
dbms_output.put_line('SID='||v_sid);

end pt;
/

Warning: Procedure created with compilation errors.

SQL> sho err
Errors for PROCEDURE PT:

LINE/COL ERROR
-------- -----------------------------------------------------------
5/1      PL/SQL: SQL Statement ignored
7/9      PL/SQL: ORA-00942: table or view does not exist
SQL>

create or replace procedure pt is
l_count integer:=0;
v_sid varchar2(50);
begin
SELECT sys_context('USERENV','DB_NAME')
   INTO v_sid
   FROM dual;
dbms_output.put_line('SID='||v_sid);

end pt;
/