[oracle] Printing the value of a variable in SQL Developer

I wanted to print the value of a particular variable which is inside an anonymous block. I am using Oracle SQL Developer. I tried using dbms_output.put_line. But it is not working. The code which I am using is shown below.

SET SERVEROUTPUT ON

DECLARE

  CTABLE USER_OBJECTS.OBJECT_NAME%TYPE;
  CCOLUMN ALL_TAB_COLS.COLUMN_NAME%TYPE;
  V_ALL_COLS VARCHAR2(500);

  CURSOR CURSOR_TABLE
    IS
    SELECT OBJECT_NAME 
    FROM USER_OBJECTS 
    WHERE OBJECT_TYPE='TABLE'
    AND OBJECT_NAME LIKE 'tb_prm_%';

  CURSOR CURSOR_COLUMNS (V_TABLE_NAME IN VARCHAR2)
    IS
    SELECT COLUMN_NAME
    FROM ALL_TAB_COLS
    WHERE TABLE_NAME = V_TABLE_NAME;

BEGIN

  OPEN CURSOR_TABLE;

  LOOP
    FETCH CURSOR_TABLE INTO CTABLE;
    EXIT WHEN CURSOR_TABLE%NOTFOUND;

    OPEN CURSOR_COLUMNS (CTABLE);

    V_ALL_COLS := NULL;

    LOOP
      FETCH CURSOR_COLUMNS INTO CCOLUMN;
      V_ALL_COLS := V_ALL_COLS || CCOLUMN;
      IF CURSOR_COLUMNS%FOUND THEN
        V_ALL_COLS := V_ALL_COLS || ', ';
      ELSE
        EXIT;
      END IF;
    END LOOP;

    DBMS_OUTPUT.PUT_LINE(V_ALL_COLS);

  END LOOP;
  CLOSE CURSOR_TABLE;

END;

And I am getting the output only as anonymous block completed.

DECLARE

  CTABLE USER_OBJECTS.OBJECT_NAME%TYPE;
  CCOLUMN ALL_TAB_COLS.COLUMN_NAME%TYPE;
  V_ALL_COLS VARCHAR2(5000);

  CURSOR CURSOR_TABLE
    IS
    SELECT OBJECT_NAME 
    FROM USER_OBJECTS 
    WHERE OBJECT_TYPE='TABLE'
    AND OBJECT_NAME LIKE 'STG%';

  CURSOR CURSOR_COLUMNS (V_TABLE_NAME IN VARCHAR2)
    IS
    SELECT COLUMN_NAME
    FROM ALL_TAB_COLS
    WHERE TABLE_NAME = V_TABLE_NAME;

BEGIN

  OPEN CURSOR_TABLE;
  LOOP
    FETCH CURSOR_TABLE INTO CTABLE;

    OPEN CURSOR_COLUMNS (CTABLE);
    V_ALL_COLS := NULL;
    LOOP

      FETCH CURSOR_COLUMNS INTO CCOLUMN;
      V_ALL_COLS := V_ALL_COLS || CCOLUMN;
      IF CURSOR_COLUMNS%FOUND THEN
        V_ALL_COLS := V_ALL_COLS || ', ';
      ELSE
        EXIT;
      END IF;
    END LOOP;
   close CURSOR_COLUMNS ;
    DBMS_OUTPUT.PUT_LINE(V_ALL_COLS);
    EXIT WHEN CURSOR_TABLE%NOTFOUND;
  END LOOP;`enter code here`
  CLOSE CURSOR_TABLE;

END;

I have added Close of second cursor. It working and getting output as well...

1 ) Go to view menu.
2 ) Select the DBMS_OUTPUT menu item.
3 ) Press Ctrl + N and select connection editor.
4 ) Execute the SET SERVEROUTPUT ON Command.
5 ) Then execute your PL/SQL Script.

select View-->DBMS Output in menu and

Make server output on First of all

1. SET SERVEROUTPUT on then

2. Go to the DBMS Output window (View->DBMS Output)

3. then Press Ctrl+N for connecting server

Go to the DBMS Output window (View->DBMS Output).

SQL Developer seems to only output the DBMS_OUTPUT text when you have explicitly turned on the DBMS_OUTPUT window pane.

Go to (Menu) VIEW -> Dbms_output to invoke the pane.

Click on the Green Plus sign to enable output for your connection and then run the code.

EDIT: Don't forget to set the buffer size according to the amount of output you are expecting.

There are 2 options:

set serveroutput on format wrapped;

or

Open the 'view' menu and click on 'dbms output'. You should get a dbms output window at the bottom of the worksheet. You then need to add the connection (for some reason this is not done automatically).