select * from t1 left join t2 on t2.sysno =t1.ASysNo left join t3 on t3.sysno =t2.ASysNo left join t4 on t4.sysno =t3.ASysNo left join t5 on t5.sysno =t4.ASysNo left join t6 on t6.sysno =t5.ASysNo left join t7 on t7.sysno =t6.ASysNo where t1.name lik
/*SQLyog 企业版 - MySQL GUI v8.14 MySQL - 5.5.40 : Database - appinfodb**********************************************************************//*!40101 SET NAMES utf8 */;/*!40101 SET SQL_MODE=''*/;/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_C
Model表创建,Url映射,Views函数处理,Html生成 根据上图,视频方向与视频分类是多对多的关系,视频分类与视频信息是一对多的关系,难度级别是单一的查询条件(与之前俩者并无关系) Models.py如下: from django.db import models class Direction(models.Model): """ 方向:自动化,测试,运维,前端 """ name = models.CharField(verbose_n
创建一个自定义函数: ; DELIMITER $$ USE `dressv_website`$$ DROP FUNCTION IF EXISTS `fn_QueryRelation`$$ CREATE DEFINER=`sa`@`%` FUNCTION `fn_QueryRelation`(AreaId INT,Relation TINYINT()) RETURNS VARCHAR() CHARSET utf8 BEGIN DECLARE sTemp VARCHAR(); DECLARE sTe
表tariff_info, 原始数据: 想要的结果:以start_time时间倒序排序, 以code分类, 查询每一类最新的一条记录 sql: SELECT a.* FROM TARIFF_INFO a, ( SELECT code, MAX (start_time) start_time FROM TARIFF_INFO GROUP BY code ) b WHERE a.start_time = b.start_time AND a.code = b.code ORDER BY a.code