DESCRIBE

CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
                  ENAME VARCHAR2(10),
                  JOB VARCHAR2(9),
                  SAL NUMBER(7, 2),
                  DEPTNO NUMBER(2));


SQL> describe emp;
 Name                                      Null?    Type
 ----------------------------------------- -------- ---------------------
 EMPNO                                     NOT NULL NUMBER(4)
 ENAME                                              VARCHAR2(10)
 JOB                                                VARCHAR2(9)
 SAL                                                NUMBER(7,2)
 DEPTNO                                             NUMBER(2)

SQL>