oracle常见语句(转载)

--==================================== 一.sql语句方面 ====================================================
--========================================================================================================
1.增加主键
   alter table TABLE_NAME add constraint KEY_NAME primary key (TABLE_COLUMN);
   指定表空间
   alter table TABLE_NAME add constraint KEY_NAME primary key (TABLE_COLUMN) using index  tablespace TABLE_SPACE_NAME;
2.增加外键
   alter table TABLE_NAME add constraint FK_NAME  foreign key (TABLE_COLUMN) references KEY_TABLE_NAME;
3.使主键或外键失效、生效
   alter table TABLE_NAME  disable(enable) constraint KEY_NAME;
4、查看各种约束
  select constraint_name,table_name,constraint_type,status from user_constraints;
  select constraint_name, constraint_type,search_condition, r_constraint_name  from user_constraints where table_name = upper('&table_name')
  select c.constraint_name,c.constraint_type,cc.column_name  
        from user_constraints c,user_cons_columns cc
        where c.owner = upper('&table_owner') and c.table_name = upper('&table_name')
        and c.owner = cc.owner and c.constraint_name = cc.constraint_name
        order by cc.position;
5、删除主键或外键
  alter table TABLE_NAME  drop constraint KEY_NAME;
6、建外键
    单字段时：create table 表名 (col1  char(8),
                                 cno   char(4)  REFERENCE course);
    多个字段时,在最后加上 Foreign Key (字段名) REFERENCE 表名(字段)
    连带删除选项 (on delete cascade
     &nbs