SQL>
SQL> SET ECHO ON
SQL> SET SERVEROUTPUT ON
SQL> DECLARE
2 a VARCHAR2(30);
3 b VARCHAR2(30);
4 c VARCHAR2(30);
5 BEGIN
6 a := ' AAA ';
7 b := ' BBB';
8 DBMS_OUTPUT.PUT_LINE(a || ' ' || b || ',');
9 END;
10 /
AAA BBB,
PL/SQL procedure successfully completed.
SQL>