create database if not exists uav_airspace DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_bin; use uav_airspace; alter table zyd_airspace modify appli_time datetime not null comment '申請日期'; alter table zyd_airspace modify start_time datetime not null comment '起始时间'; alter table zyd_airspace modify end_time datetime not null comment '结束时间'; ALTER TABLE `uav_airspace`.`zyd_airspace` MODIFY COLUMN `area_range` text NOT NULL COMMENT '空域范围';