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MySQL的安装与基础操作
安装过程我们需要通过开启管理员权限来安装,切记!!!否则会由于权限不足导致无法安装。Windows 上安装 MySQL 相对来说会较为简单,官网下载 zip 包。下载完后,我们将 zip 包解压到相应的目录,这里我将解压后的文件夹放在 E盘下,并修改了mysql文件夹的名字(去掉了mysql后面跟的版本号),所以我的安装目录是E:\mysql接下来我们需要配置下 MySQL 的配置文件,在该文...原创 2019-03-17 17:52:37 · 277 阅读 · 0 评论 -
SQLZOO答案:The JOIN operation(全部通过)
3、Modify it to show the player, teamid, stadium and mdate for every German goal.SELECT player,teamid,stadium, mdate FROM game JOIN goal ON (id=matchid) WHERE teamid = 'GER';4、Show the team1, team...原创 2019-04-15 16:49:06 · 932 阅读 · 1 评论 -
SQLZOO答案 : SELECT within SELECT Tutoria(全部通过)
1、List each country name where the population is larger than that of ‘Russia’.SELECT name FROM world WHERE population > (SELECT population FROM world WHERE name='Russia') 2、Show the c...原创 2019-04-13 14:18:44 · 531 阅读 · 0 评论 -
inner join 与 natural join的区别
首先,join默认是inner join我一开始以为这两个可以互换比如actor(actorid为主键)actoridname1小明2小亮3小红movie(movieid,actorid都为主键)movieidactorid111223那么把这两张表连接起来有两种方法INNER JOINSELEC...原创 2019-04-17 11:30:44 · 5362 阅读 · 1 评论 -
SQLZOO答案: More JOIN operations(全部通过)
前十题都太简单了,就不给答案了11、Which were the busiest years for ‘John Travolta’, show the year and the number of movies he made each year for any year in which he made more than 2 movies.SELECT yr,COUNT(title) F...原创 2019-04-17 22:31:11 · 2267 阅读 · 0 评论