Oracle PL/SQL Tutorial/Table/Drop Column

Материал из SQL эксперт
Версия от 13:05, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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Drop a just added column

   <source lang="sql">

SQL> SQL> SQL> create table registrations

 2  ( attendee    NUMBER(4)
 3  , course      VARCHAR2(6)
 4  , begindate   DATE
 5  , evaluation  NUMBER(1)) ;

Table created. SQL> SQL> SQL> insert into registrations values (1, "SQL",date "1999-04-12",4 ); 1 row created. SQL> insert into registrations values (2, "SQL",date "1999-12-13",NULL); 1 row created. SQL> insert into registrations values (3, "SQL",date "1999-12-13",NULL); 1 row created. SQL> insert into registrations values (4, "OAU",date "1999-08-10",4 ); 1 row created. SQL> insert into registrations values (5, "OAU",date "2000-09-27",5 ); 1 row created. SQL> insert into registrations values (6, "JAV",date "1999-12-13",2 ); 1 row created. SQL> insert into registrations values (7, "JAV",date "2000-02-01",4 ); 1 row created. SQL> insert into registrations values (8, "JAV",date "2000-02-01",5 ); 1 row created. SQL> insert into registrations values (9, "XML",date "2000-02-03",4 ); 1 row created. SQL> insert into registrations values (10,"XML",date "2000-02-03",5 ); 1 row created. SQL> insert into registrations values (1, "PLS",date "2000-09-11",NULL); 1 row created. SQL> insert into registrations values (2, "PLS",date "2000-09-11",NULL); 1 row created. SQL> insert into registrations values (3, "PLS",date "2000-09-11",NULL); 1 row created. SQL> SQL> SQL> alter table registrations

 2  add  (entered_by number(4) default 7839 not null);

Table altered. SQL> SQL> alter table registrations

 2  drop  column entered_by;

Table altered. SQL> SQL> drop table registrations; Table dropped. SQL></source>