Oracle PL/SQL/SQL Plus/SERVEROUTPUT

Make sure SQL*Plus SERVEROUTPUT setting is on

 
SQL> SET SERVEROUTPUT ON SIZE 1000000
SQL>
SQL> BEGIN
  2     DBMS_OUTPUT.PUT_LINE("hello, world");
  3  END;
  4  /
hello, world
PL/SQL procedure successfully completed.
SQL>
SQL>

SET SERVEROUTPUT OFF/ON

  
SQL>
SQL>
SQL> SET ECHO ON
SQL> SET SERVEROUTPUT OFF
SQL>
SQL> BEGIN
  2    DBMS_OUTPUT.ENABLE (2000);
  3    DBMS_OUTPUT.PUT_LINE("Three names will be written.");
  4    DBMS_OUTPUT.PUT("J");
  5    DBMS_OUTPUT.NEW_LINE;
  6    DBMS_OUTPUT.PUT("S");
  7    DBMS_OUTPUT.NEW_LINE;
  8    DBMS_OUTPUT.PUT("T");
  9    DBMS_OUTPUT.NEW_LINE;
 10  END;
 11  /
PL/SQL procedure successfully completed.
SQL>
SQL> SET SERVEROUTPUT ON
SQL> DECLARE
  2    throw_away VARCHAR2(50);
  3    names DBMS_OUTPUT.CHARARR;
  4    lines_to_get NUMBER;
  5    inx1 NUMBER;
  6    combined_names VARCHAR2(80);
  7    status NUMBER;
  8  BEGIN
  9    DBMS_OUTPUT.GET_LINE(throw_away, status);
 10
 11    lines_to_get := 3;
 12    DBMS_OUTPUT.GET_LINES(names, lines_to_get);
 13
 14    combined_names := "";
 15    FOR inx1 IN 1 .. lines_to_get LOOP
 16      IF inx1 > 1 THEN
 17        combined_names := combined_names || " and ";
 18      END IF;
 19
 20      combined_names := combined_names || names(inx1);
 21    END LOOP;
 22    DBMS_OUTPUT.PUT_LINE(combined_names);
 23  END;
 24  /
J and S and T
PL/SQL procedure successfully completed.
SQL>
SQL> --

SET SERVEROUTPUT ON SIZE 1000000

 
SQL> SET SERVEROUTPUT ON SIZE 1000000
SQL> BEGIN
  2    dbms_output.put_line("Hello World.");
  3  END;
  4  /
Hello World.
PL/SQL procedure successfully completed.
SQL>

The SET SERVEROUTPUT Command

  
SQL> SET SERVEROUTPUT ON
SQL> BEGIN
  2      dbms_output.put_line("This is the first line");
  3      dbms_output.put_line("This is the second line");
  4      dbms_output.put_line("This is the last line");
  5  END;
  6  /
This is the first line
This is the second line
This is the last line
PL/SQL procedure successfully completed.

TRUNCATED formatting option: each line of the displayed output is truncated exactly at the length specified by the LINESIZE variable.

  
SQL>
SQL> SET SERVEROUTPUT ON FORMAT TRUNCATED
SQL> SET LINESIZE 20
SQL> BEGIN
  2   DBMS_OUTPUT.PUT_LINE("After the first 20 characters please");
  3   DBMS_OUTPUT.PUT_LINE("continue on the second line");
  4  END;
  5  /
After the first 20 c
continue on the seco
PL/SQL procedure successfully completed.
SQL>

WORD_WRAPPED option for FORMAT wraps each line to the length specified by the value of the LINESIZE variable

  
SQL>
SQL> SET SERVEROUTPUT ON FORMAT WORD_WRAPPED
SQL> SET LINESIZE 20
SQL> BEGIN
  2      dbms_output.put_line("After the first 20 characters please");
  3      dbms_output.put_line("continue on the second line");
  4  END;
  5  /
After the first 20
characters please
continue on the
second line
PL/SQL procedure successfully completed.