两个表，
一个存储值班情况，
一个存储用户情况
create table t_duty
(
tudy_date date not null,
lead_id number not null,
worker_id number not null
)
;
comment on table t_duty
is '值班表';
comment on column t_duty.tudy_date
is '值班日期';
comment on column t_duty.lead_id
is '领导ID';
comment on column t_duty.worker_id
is '员工ID';
create table t_user
(
id number not null,
name varchar2(20) not null,
lead char(1) not null
)
;
comment on column t_user.id
is '职员ID';
comment on column t_user.name
is '职员姓名';
comment on column t_user.lead
is '是否是领导';
