mysql 追加update_time、create_time、id三字段

本文介绍如何使用SQL语句来实现字段的自动填充当前时间戳,包括数据创建时的默认值设置以及数据更新时的时间自动更新。此外,还展示了如何修改表中的主键字段为自增长类型。

紧当数据创建时设置值

alter table tbl_books modify create_time datetime  not null default current_timestamp

当数据被修改时该字段自动更新

alter table tableName add update_time datetime not null default current_timestamp on update current_timestamp

修改主键自动增加

alter table tbl_books modify id bigint auto_increment
下面SQL则呢创建索引SELECT t.live_room_id AS liveRoomId, t.CODE AS CODE, t.live_type AS liveType, t.mode_app AS modeApp, t.mode_pc AS modePc, t.mode_courseware AS modeCourseware, t.live_room_name AS liveRoomName, t.live_start_time AS liveStartTime, t.live_end_time AS liveEndTime, t.really_start_time AS reallyStartTime, t.really_end_time AS reallyEndTime, t.is_clear AS isClear, t.live_img AS liveImg, t.is_must_phone AS isMustPhone, t.live_time_length AS liveTimeLength, t.display_form AS displayForm, CASE WHEN t.really_start_time IS NULL AND t.live_end_time > NOW() THEN '未开始' WHEN t.really_start_time IS NOT NULL AND t.really_end_time IS NULL THEN '直播中' WHEN ( t.really_end_time IS NOT NULL OR ( t.really_start_time IS NULL AND t.live_end_time <= NOW())) THEN '回放中' ELSE NULL END AS STATUS FROM live_room t WHERE t.is_delete = 0 AND t.sale_way = 1 AND t.tenant_id = 2155 AND t.live_room_id NOT IN ( SELECT liveRoom.live_room_id FROM live_room liveRoom WHERE liveRoom.is_delete = 0 AND liveRoom.tenant_id = 2155 AND ( liveRoom.really_end_time IS NOT NULL OR ( liveRoom.really_start_time IS NULL AND liveRoom.live_end_time <= NOW())) ) AND CASE WHEN ( t.really_end_time IS NOT NULL OR ( t.really_start_time IS NULL AND t.live_end_time <= NOW())) THEN t.playback_make_status = 1 AND t.playback_view_status = 1 AND ( t.playback_view_close_time IS NULL OR t.playback_view_close_time <= now() ) AND t.bjy_video_status = 100 ELSE 1 = 1 END ORDER BY CASE STATUS WHEN '回放中' THEN 2 WHEN '直播中' THEN 0 WHEN '已结束' THEN 1 ELSE 3 END ASC, t.create_time ASC LIMIT 5
09-08
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