Oracle SQL - DESCRIBE command on a view

Introduction

The following code shows that you can use the SQL*Plus DESCRIBE command on a view.

Demo

SQL>
SQL> drop table emp;

Table dropped.-- from  w  w  w . j a  v a 2 s.  c  om

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> insert into emp values(7001,'SMITH','N',  'TRAINER', 7902,date '1975-12-17',  1800 , NULL, 20);
SQL> insert into emp values(7002,'ALLEN','JAM','SALESREP',7006,date '1971-05-20',  1600, 300,   30);
SQL> insert into emp values(7003,'WARD', 'TF' ,'SALESREP',7006,date '1972-03-02',  1250, 500,   10);
SQL> insert into emp values(7004,'JACK', 'JM', 'MANAGER', 7009,date '1977-04-02',  2975, NULL,  20);
SQL> insert into emp values(7005,'BROWN','P',  'SALESREP',7006,date '1976-09-28',  1250, 1400,  30);
SQL> insert into emp values(7006,'BLAKE','R',  'MANAGER', 7009,date '1973-11-01',  2850, NULL,  10);
SQL> insert into emp values(7007,'CLARK','AB', 'MANAGER', 7009,date '1975-06-09',  2450, NULL,  10);
SQL> insert into emp values(7008,'SCOTT','DEF','TRAINER', 7004,date '1979-11-26',  3000, NULL,  20);
SQL> insert into emp values(7009,'KING', 'CC', 'DIRECTOR',NULL,date '1972-10-17',  5000, NULL,  10);
SQL> insert into emp values(7010,'BREAD','JJ', 'SALESREP',7006,date '1978-09-28',  1500, 0,     30);
SQL> insert into emp values(7011,'ADAMS','AA', 'TRAINER', 7008,date '1976-12-30',  1100, NULL,  20);
SQL> insert into emp values(7012,'JONES','R',  'ADMIN',   7006,date '1979-10-03',  8000, NULL,  30);
SQL> insert into emp values(7902,'FORD', 'MG', 'TRAINER', 7004,date '1979-02-13',  3000, NULL,  20);
SQL> insert into emp values(7934,'MARY', 'ABC','ADMIN',   7007,date '1972-01-23',  1300, NULL,  10);
SQL>
SQL> create or replace view empdept_v as      -- This line is added
  2  select e.empno
  3  ,      e.ENAME
  4  ,      e.init
  5  ,      d.dname
  6  ,      d.location
  7  ,      m.ENAME    as MANAGER
  8  from   emp   e
  9  join
 10  departments d using (deptno)
 11  join
 12  emp   m on (m.empno = d.mgr);

View created.

SQL>
SQL> describe empdept_v;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 EMPNO                                     NOT NULL NUMBER(4)
 ENAME                                     NOT NULL VARCHAR2(8)
 INIT                                      NOT NULL VARCHAR2(5)
 DNAME                                     NOT NULL VARCHAR2(10)
 LOCATION                                  NOT NULL VARCHAR2(8)
 MANAGER                                   NOT NULL VARCHAR2(8)

SQL>
SQL> select * from empdept_v where manager = 'CLARK';

     EMPNO ENAME    INIT  DNAME      LOCATION MANAGER
---------- -------- ----- ---------- -------- --------
      7934 MARY     ABC   ACCOUNTING NEW YORK CLARK
      7009 KING     CC    ACCOUNTING NEW YORK CLARK
      7007 CLARK    AB    ACCOUNTING NEW YORK CLARK
      7006 BLAKE    R     ACCOUNTING NEW YORK CLARK
      7003 WARD     TF    ACCOUNTING NEW YORK CLARK

SQL>

Related Topic