This is complete exercise of video tutorials
SQL> select nvl() from dual;
select nvl() from dual
*
ERROR at line 1:
ORA-00909: invalid number of arguments
SQL> select nvl(12) from dual;
select nvl(12) from dual
*
ERROR at line 1:
ORA-00909: invalid number of arguments
SQL> select nvl(,12) from dual;
select nvl(,12) from dual
*
ERROR at line 1:
ORA-00936: missing expression
SQL> select nvl(12,) from dual;
select nvl(12,) from dual
*
ERROR at line 1:
ORA-00936: missing expression
SQL> select nvl(100,200) from dual;
NVL(100,200)
------------
100
SQL> select nvl(null,200) from dual;
NVL(NULL,200)
-------------
200
SQL> select nvl(100,null) from dual;
NVL(100,NULL)
-------------
100
SQL> select nvl(null,null) from dual;
N
-
SQL> select nvl(null,100,200) from dual;
select nvl(null,100,200) from dual
*
ERROR at line 1:
ORA-00909: invalid number of arguments
SQL> select nvl(100,'Hello') from dual;
select nvl(100,'Hello') from dual
*
ERROR at line 1:
ORA-01722: invalid number
SQL> select nvl(100,'200') from dual;
NVL(100,'200')
--------------
100
SQL> select nvl('Hello','Cello') from dual;
NVL('
-----
Hello
SQL> select nvl(null,'Cello') from dual;
NVL(N
-----
Cello
SQL> select nvl('Hello','200') from dual;
NVL('
-----
Hello
Thanks