实习第七周

    CREATE TABLE `t_user` (
        `Id` int(11) NOT NULL AUTO_INCREMENT, 
        `username` varchar(18) NOT NULL unique, 
        `password` varchar(18) NOT NULL, 
        PRIMARY KEY (`Id`) 
    ) ENGINE=InnoDB AUTO_INCREMENT=1018 DEFAULT CHARSET=gbk;

ALERT TABLE user ADD UNIQUE(username);

let mySet = new Set();
//添加值
mySet.add(1)
//判断是否存在
mySet.has(1)
//删除值
mySet.delete(1)
//查看大小
mySet.size()查看大小
//Set与Array之间的转换
// Array -> Set
var mySet = new Set(myArray)
// Set -> Array
var myArray = [...mySet]

show create database **mytest **

alert database **mytest **character set=**utf8**

$redis-cli
127.0.0.1>flushall