-- Your SQL goes here

create table kecheng
(
    id             varchar   not null,
    group_id       varchar,
    kecheng_name   varchar   not null,
    kecheng_desc   varchar,
    teacher_id     varchar   not null,
    student_id     varchar   not null,
    start_from     timestamp not null,
    end_by         timestamp not null,
    kecheng_status varchar   not null
);

create unique index kecheng_id_uindex
    on kecheng (id);

alter table kecheng
    add constraint kecheng_pk
        primary key (id);