Bo's Oracle Station

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第26次活动:2017-10-23(星期一晚上7:00-9:30)

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发表于 2017-10-23 19:50:00 | 显示全部楼层 |阅读模式
  1. select  table_name from user_tables order by 1 desc  ;

  2. create table t05110_t ( a  number ) ;

  3. alter table t05110_t add  (b varchar2(20) ,  c date );

  4. alter table t05110_t modify (c number ) ;

  5. insert into t05110_t values ( 1, 'A', 10) ;

  6. ---alter table t05110_t modify (c varchar2(20)) ;

  7. alter table t05110_t modify (b char(21)) ;

  8. --------------------------
  9. alter table t05110_t drop column  b;

  10. alter table t05110_t add ( b number  , d number ,  e number ) ;

  11. select * from t05110_t;

  12. alter table t05110_t drop ( a,e ) ;
  13.   
  14. select * from t05110_t;
  15. --------
  16. alter table t05110_t set  unused  column  c ;

  17. ----
  18. select  *  from dict where table_name like '%UNUSED%';
  19. select  * from user_unused_col_tabs;
  20. ---
  21. alter table  t05110_t  drop unused columns;
  22. -----

  23. alter table t05110_t rename column b to bb;
  24. -----
  25. rename t05110_t to t05110_t1;

  26. select * from  t05110_t1;

  27. alter table t05110_t1 read only;

  28. insert into  t05110_t1 values (1,11);

  29. alter table t05110_t1 read write;

  30. insert into  t05110_t1 values (1,11);
  31. -----


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  1. create  or replace  view v1 as
  2. select e.employee_id,  e.last_name,  e.email,  e.department_id  , d.department_name
  3. from employees e, departments d
  4. where e.department_id=d.department_id   order by 1;

  5. select  * from v1;

  6. update v1 set email='XXX' where email='SKING';

  7.   
  8. update v1 set  department_id=60 where employee_id=100;

  9.   update v1 set  department_name='YYY' where email='XXX';
  10.   
  11.   create table t05111_a  ( a  number ) ;
  12.   
  13.   create view v2 as select a*2  b   from t05111_a;
  14.   
  15.   insert into t05111_a values (8) ;
  16.   
  17.   select  * from v2;
  18.   
  19.   update v2 set b=10 ;
  20.   ---
  21.   CREATE   or replace VIEW         empvu80
  22. AS SELECT  employee_id, last_name, salary , department_id
  23.     FROM    employees
  24.     WHERE   department_id = 80  order by employee_id
  25.     with check option constraint v2_chk;
  26. ----
  27. select  * from  empvu80;

  28. update empvu80 set  department_id=60 where employee_id=145;

  29. select  * from user_constraints  order by table_name;

  30. update empvu80 set  department_id=60 where employee_id=146;
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  1. select  * from seq[        DISCUZ_CODE_5        ]nbsp; order by 1 desc;

  2. select  * from dba_sequences  s where s.sequence_owner='HR'
  3. and s.sequence_name like 'SEQ%';
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