Is it possible to output a SELECT statement from a PL/SQL block?

You can do this in Oracle 12.1 or above:

declare    rc sys_refcursor;begin    open rc for select * from dual;    dbms_sql.return_result(rc);end;

I don't have DBVisualizer to test with, but that should probably be your starting point.

For more details, see Implicit Result Sets in the Oracle 12.1 New Features Guide, Oracle Base etc.

For earlier versions, depending on the tool you might be able to use ref cursor bind variables like this example from SQL*Plus:

set autoprint onvar rc refcursorbegin    open :rc for select count(*) from dual;end;/PL/SQL procedure successfully completed.  COUNT(*)----------         11 row selected.

It depends on what you need the result for.

If you are sure that there's going to be only 1 row, use implicit cursor:

DECLARE   v_foo foobar.foo%TYPE;   v_bar foobar.bar%TYPE;BEGIN   SELECT foo,bar FROM foobar INTO v_foo, v_bar;   -- Print the foo and bar values   dbms_output.put_line('foo=' || v_foo || ', bar=' || v_bar);EXCEPTION   WHEN NO_DATA_FOUND THEN     -- No rows selected, insert your exception handler here   WHEN TOO_MANY_ROWS THEN     -- More than 1 row seleced, insert your exception handler hereEND;

If you want to select more than 1 row, you can use either an explicit cursor:

DECLARE   CURSOR cur_foobar IS     SELECT foo, bar FROM foobar;   v_foo foobar.foo%TYPE;   v_bar foobar.bar%TYPE;BEGIN   -- Open the cursor and loop through the records   OPEN cur_foobar;   LOOP      FETCH cur_foobar INTO v_foo, v_bar;      EXIT WHEN cur_foobar%NOTFOUND;      -- Print the foo and bar values      dbms_output.put_line('foo=' || v_foo || ', bar=' || v_bar);   END LOOP;   CLOSE cur_foobar;END;

or use another type of cursor:

BEGIN   -- Open the cursor and loop through the records   FOR v_rec IN (SELECT foo, bar FROM foobar) LOOP          -- Print the foo and bar values   dbms_output.put_line('foo=' || v_rec.foo || ', bar=' || v_rec.bar);   END LOOP;END;

Create a function in a package and return a SYS_REFCURSOR:

FUNCTION Function1 return SYS_REFCURSOR IS        l_cursor SYS_REFCURSOR;       BEGIN          open l_cursor for SELECT foo,bar FROM foobar;           return l_cursor; END Function1;