oracle创建表增加字段sql脚本

oracle comment on的用法

oracle中用comment on命令给表或字段加以说明，语法如下：

COMMENT ON

{ TABLE [ schema. ]

{ table | view }

| COLUMN [ schema. ]

{ table. | view. | materialized_view. } column

| OPERATOR [ schema. ] operator

| INDEXTYPE [ schema. ] indextype

| MATERIALIZED VIEW materialized_view

}

IS ‘text’ ;

用法如下：

1.对表的说明

comment on table table_name is ‘comments_on_tab_information’;

2.对表中列的说明

comment on column table.column_name is ‘comments_on_col_information’;

3.查看表的说明

SQL> select * from user_tab_comments where TABLE_NAME=’EMPLOYEES’;

TABLE_NAME TABLE_TYPE COMMENTS

EMPLOYEES TABLE 员工表

SQL> select * from user_tab_comments where comments is not null;

TABLE_NAME TABLE_TYPE COMMENTS

EMPLOYEES TABLE 员工表

4.查看表中列的说明

SQL> select * from user_col_comments where TABLE_NAME=’EMPLOYEES’;

TABLE_NAME COLUMN_NAME COMMENTS

EMPLOYEES EMPLOYEE_ID

EMPLOYEES MANAGER_ID

EMPLOYEES FIRST_NAME

EMPLOYEES LAST_NAME

EMPLOYEES TITLE

EMPLOYEES SALARY 员工薪水

SQL> select * from user_col_comments where comments is not null;

TABLE_NAME COLUMN_NAME COMMENTS

EMPLOYEES SALARY 员工薪水

5.我们也可以从下面这些视图中查看表级和列级说明：

ALL_COL_COMMENTS

USER_COL_COMMENTS

ALL_TAB_COMMENTS

USER_TAB_COMMENTS

6.删除表级说明，也就是将其置为空

SQL> comment on table employees is ”;

Comment added

SQL> select * from user_tab_comments where TABLE_NAME=’EMPLOYEES’;

TABLE_NAME TABLE_TYPE COMMENTS

EMPLOYEES TABLE

7.删除列级说明，也是将其置为空

SQL> comment on column employees.salary is ”;

Comment added

SQL> select * from user_col_comments where TABLE_NAME=’EMPLOYEES’;

TABLE_NAME COLUMN_NAME COMMENTS

EMPLOYEES EMPLOYEE_ID

EMPLOYEES MANAGER_ID

EMPLOYEES FIRST_NAME

EMPLOYEES LAST_NAME

EMPLOYEES TITLE

EMPLOYEES SALARY

下面我展示一下项目开发中的实例来做参考

-- Create table
create table F_S_WASH_TASK
(
task_id         NUMBER(16) not null,
task_no         VARCHAR2(16) not null,
equip_categ     VARCHAR2(8),
task_status     VARCHAR2(8) not null,
start_date      DATE not null,
end_date        DATE,
task_num        NUMBER(15),
org_no          VARCHAR2(16) not null,
creator_no      VARCHAR2(16),
create_date     DATE,
exec_org_no     VARCHAR2(16),
team_no         VARCHAR2(16),
executor_no     VARCHAR2(16),
parent_task_id  NUMBER,
priority        VARCHAR2(8) not null,
remark          VARCHAR2(32),
finish_remark   VARCHAR2(256),
wiring_mode     VARCHAR2(8),
finished_date   DATE,
real_start_date DATE
)
tablespace MPAC_A
pctfree 10
initrans 1
maxtrans 255
storage
(
initial 64
next 1
minextents 1
maxextents unlimited
);
-- Add comments to the table
comment on table F_S_WASH_TASK
is '清洁分选任务表';
-- Add comments to the columns
comment on column F_S_WASH_TASK.task_id
is '唯一标识';
comment on column F_S_WASH_TASK.task_no
is '清洁分选任务编';
comment on column F_S_WASH_TASK.equip_categ
is '设备类别，参见计量标准代码：设备类别VW_EQUIP_CATEG';
comment on column F_S_WASH_TASK.task_status
is '任务状态，01初始、02待分配、03已分配、04执行中、05执行完成、06已完成';
comment on column F_S_WASH_TASK.start_date
is '任务开始时间';
comment on column F_S_WASH_TASK.end_date
is '任务结束时间';
comment on column F_S_WASH_TASK.task_num
is '任务数量';
comment on column F_S_WASH_TASK.org_no
is '创建单位编号';
comment on column F_S_WASH_TASK.creator_no
is '创建人';
comment on column F_S_WASH_TASK.create_date
is '创建时间';
comment on column F_S_WASH_TASK.exec_org_no
is '执行单位';
comment on column F_S_WASH_TASK.team_no
is '执行班组';
comment on column F_S_WASH_TASK.executor_no
is '执行人';
comment on column F_S_WASH_TASK.parent_task_id
is '父任务标识';
comment on column F_S_WASH_TASK.priority
is '任务优先级 01一般 02 重要 03紧急';
comment on column F_S_WASH_TASK.remark
is '备注';
comment on column F_S_WASH_TASK.finish_remark
is '任务完成备注';
comment on column F_S_WASH_TASK.wiring_mode
is '接线方式';
comment on column F_S_WASH_TASK.finished_date
is '任务完成日期';
comment on column F_S_WASH_TASK.real_start_date
is '任务实际开始时间';
-- Create/Recreate primary, unique and foreign key constraints
alter table F_S_WASH_TASK
add constraint PK_F_S_WASH_TASK primary key (TASK_ID)
using index
tablespace MPAC_A
pctfree 10
initrans 2
maxtrans 255
storage
(
initial 64K
next 1M
minextents 1
maxextents unlimited
);