create database demo;

CREATE TABLE `school`
(
    `id`        bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
    `name`  varchar(64)  NOT NULL COMMENT '名称',
    `address`  varchar(128) NOT NULL COMMENT '密码',
    `create_dt` datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
    `update_dt` datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '修改时间',
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='学校';

CREATE TABLE `student`
(
    `id`        bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
    `name`  varchar(64)  NOT NULL COMMENT '姓名',
    `age`  tinyint NOT NULL COMMENT '年龄',
    `create_dt` datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
    `update_dt` datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '修改时间',
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='学生';

CREATE TABLE `teacher`
(
    `id`        bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
    `name`  varchar(64)  NOT NULL COMMENT '姓名',
    `age`  tinyint NOT NULL COMMENT '年龄',
    `create_dt` datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
    `update_dt` datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '修改时间',
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='教师';

CREATE TABLE `school_student_teacher`
(
    `id`        bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
    `school_id`  bigint(20)  NOT NULL COMMENT '学校id',
    `teacher_id`  bigint(20)  NOT NULL COMMENT '教师id',
    `student_id`  bigint(20)  NOT NULL COMMENT '学生id',
    `create_dt` datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
    `update_dt` datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '修改时间',
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='学校学生老师表';