To get a quick overview of the structure of a table, for example, to see the column names and the data types, use the SQL*Plus DESCRIBE command.
SQL> SQL>-- w w w. j a v a 2 s. c o m SQL> drop table emp; Table dropped. SQL> create table emp( 2 empno NUMBER(4) primary key, 3 ename VARCHAR2(8) not null , 4 init VARCHAR2(5) not null , 5 job VARCHAR2(8) , 6 mgr NUMBER(4) , 7 bdate DATE not null , 8 msal NUMBER(6,2) not null , 9 comm NUMBER(6,2) , 10 deptno NUMBER(2) default 10) ; SQL> SQL> descr emp Name Null? Type ----------------------------------------- -------- ---------------------------- EMPNO NOT NULL NUMBER(4) ENAME NOT NULL VARCHAR2(8) INIT NOT NULL VARCHAR2(5) JOB VARCHAR2(8) MGR NUMBER(4) BDATE NOT NULL DATE MSAL NOT NULL NUMBER(6,2) COMM NUMBER(6,2) DEPTNO NUMBER(2) SQL>