Redis基本数据类型Zset Zset在set的基础上增加了一个值set key value zset key score value127.0.0.1:6379> zadd myzset 1 A #添加一个值 (integer) 1 127.0.0.1:6379> zadd myzset 2 B 3 C #添加多个值 (integer) 2 127.0.0.1:6379> zrange myzset 0 -1 1) "A" 2) "B" 3) "C" 127.0.0.1:6379> #排序 127.0.0.1:6379> zadd grade 100 sun (integer) 1 127.0.0.1:6379> zadd grade 80 liubo (integer) 1 127.0.0.1:6379> zadd grade 66 giao (integer) 1 127.0.0.1:6379> zrangebyscore grade -inf +inf #显示全部的学生（升序） 1) "giao" 2) "liubo" 3) "sun" 127.0.0.1:6379> zrevrange grade 0 -1 #降序排列 1) "sun" 2) "giao" 127.0.0.1:6379> 127.0.0.1:6379> zrangebyscore grade -inf +inf withscores #显示全部的学生并附带分数（升序） 1) "giao" 2) "66" 3) "liubo" 4) "80" 5) "sun" 6) "100" 127.0.0.1:6379> zrangebyscore grade -inf 90 withscores #显示成绩小于90的学生（升序） 1) "giao" 2) "66" 3) "liubo" 4) "80" 127.0.0.1:6379> # zrem 移除元素 127.0.0.1:6379> zrange grade 0 -1 1) "giao" 2) "liubo" 3) "sun" 127.0.0.1:6379> zrem grade liubo (integer) 1 127.0.0.1:6379> zrange grade 0 -1 1) "giao" 2) "sun" # zcard 获取有序集合中的个数 127.0.0.1:6379> zcard grade (integer) 2 127.0.0.1:6379> # zcount 获取指定区间的数量 127.0.0.1:6379> zcount grade 1 2 Zset可用于成绩表、工资表排序、网站排行榜等方面

Redis基本数据类型Set Set（集合）set中的值不能重读，与list操作一样，set操作以s开头127.0.0.1:6379> sadd set hello #添加值 (integer) 1 127.0.0.1:6379> sadd set world (integer) 1 127.0.0.1:6379> smembers set #查看指定set的所有值 1) "hello" 2) "world" 127.0.0.1:6379> sismember set hello #判断某一个值是否存在set集合中 (integer) 1 127.0.0.1:6379> scard set #获取set集合中内容元素的个数 (integer) 2 127.0.0.1:6379> # srem 移除元素 127.0.0.1:6379> smembers set #移除set集合中的指定元素 1) "hello1" 2) "hello2" 3) "hello" 4) "hello3" 127.0.0.1:6379> srem set hello (integer) 1 127.0.0.1:6379> smembers set 1) "hello1" 2) "hello2" 3) "hello3" 127.0.0.1:6379> # srandmember 随机抽取元素 127.0.0.1:6379> srandmember set #随机抽取一个元素 "hello1" 127.0.0.1:6379> srandmember set "hello2" 127.0.0.1:6379> srandmember set 2 #随机抽取指定个数的元素 1) "hello1" 2) "hello2" 127.0.0.1:6379> srandmember set 2 1) "hello" 2) "hello3" 127.0.0.1:6379> # spop 随机移除set集合中的元素 127.0.0.1:6379> spop set "hello3" 127.0.0.1:6379> spop set "hello" 127.0.0.1:6379> # smove 移动指定元素到其他set集合中 127.0.0.1:6379> sadd set01 hello (integer) 1 127.0.0.1:6379> sadd set01 bihao (integer) 1 127.0.0.1:6379> sadd set01 xiexie (integer) 1 127.0.0.1:6379> sadd set02 chouxiang (integer) 1 127.0.0.1:6379> smove set01 set02 xiexie (integer) 1 127.0.0.1:6379> smembers set01 1) "hello" 2) "bihao" 127.0.0.1:6379> smembers set02 1) "chouxiang" 2) "xiexie" 127.0.0.1:6379> # 差集 交集 并集 127.0.0.1:6379> smembers set01 1) "a" 2) "d" 3) "b" 4) "c" 5) "e" 127.0.0.1:6379> smembers set02 1) "b" 2) "c" 127.0.0.1:6379> sdiff set01 set02 #差集 1) "e" 2) "a" 3) "d" 127.0.0.1:6379> sinter set02 set02 #交集 1) "b" 2) "c" 127.0.0.1:6379> sunion set01 set02 #并集 1) "c" 2) "e" 3) "b" 4) "a" 5) "d" 具体应用如：共同关注，二度好友，（推荐好友，可能认识的人）六度分割理论

Redis基本数据类型Hash Hashkey-value键值对key-map===>此时将value换成了一个map集合hash的本质与String没有太大的区别127.0.0.1:6379> hset hash field nihao #set一个具体的key-value (integer) 1 127.0.0.1:6379> hget hash field "nihao" 127.0.0.1:6379> hmset myhash field01 nihao filed02 xiexie #set多个key-value OK 127.0.0.1:6379> hmget myhash field01 filed02 #获取多个字段值 1) "nihao" 2) "xiexie" 127.0.0.1:6379> hgetall myhash #获取全部的数据 1) "field01" 2) "nihao" 3) "filed02" 4) "xiexie" 127.0.0.1:6379> # hdel 删除hash指定key字段，key对应的value值也同时被删除 127.0.0.1:6379> hdel myhash filed02 (integer) 1 127.0.0.1:6379> hgetall myhash 1) "field01" 2) "nihao" 127.0.0.1:6379> # hlen 获取hash表的字段数量 127.0.0.1:6379> hgetall myhash 1) "field01" 2) "nihao" 3) "field02" 4) "xiexie" 127.0.0.1:6379> hlen myhash (integer) 2 # hexists 判断hash中指定字段是否存在 127.0.0.1:6379> hgetall myhash 1) "field01" 2) "nihao" 3) "field02" 4) "xiexie" 127.0.0.1:6379> hexists myhash field01 (integer) 1 127.0.0.1:6379> 127.0.0.1:6379> hkeys myhash #只获取所有的field字段 1) "field01" 2) "field02" 127.0.0.1:6379> hvals myhash #只获取所有的value值 1) "nihao" 2) "xiexie" 127.0.0.1:6379> 127.0.0.1:6379> hset myhash field03 2 (integer) 1 127.0.0.1:6379> hincrby myhash field03 1 #设置自增 (integer) 3 127.0.0.1:6379> hsetnx myhash field04 ceshi #如果不存在则创建 (integer) 1 127.0.0.1:6379> hsetnx myhash field04 ceshi01 #如果存在则不能创建 (integer) 0 hash更适合对象的存储（如：用户信息变更，经常改动的数据等），String更适合字符串的存储。

Redis基本数据类型List List（列表）所有的List命令都是以l开头的#插入 127.0.0.1:6379> lpush list a #将一个或多个值插入到列表头部 (integer) 1 127.0.0.1:6379> lpush list b (integer) 2 127.0.0.1:6379> lpush list c (integer) 3 127.0.0.1:6379> lrange list 0 -1 #range [key] 0 -1获取全部的值 1) "c" #后进先出（栈） 2) "b" 3) "a" 127.0.0.1:6379> lrange list 0 1 1) "c" 2) "b" 127.0.0.1:6379> rpush list d #rpush从头部插入 (integer) 4 127.0.0.1:6379> lrange list 0 -1 1) "c" 2) "b" 3) "a" 4) "d" 127.0.0.1:6379> #移除 127.0.0.1:6379> lrange list 0 -1 1) "c" 2) "b" 3) "a" 4) "d" 127.0.0.1:6379> lpop list #移除第一个元素 "c" 127.0.0.1:6379> lrange list 0 -1 1) "b" 2) "a" 3) "d" 127.0.0.1:6379> rpop list #移除最后一个元素（移除同样遵循栈后进先出的原则） "d" 127.0.0.1:6379> lrange list 0 -1 1) "b" 2) "a" 127.0.0.1:6379> #获取下标 127.0.0.1:6379> lrange list 0 -1 1) "b" 2) "a" 127.0.0.1:6379> lindex list 1 #通过下标获取list中的值[0,1,2,3...]，注意须于插入时的坐标区分 "a" 127.0.0.1:6379> lindex list 0 "b" 127.0.0.1:6379> # llen 长度 127.0.0.1:6379> lrange list 0 -1 1) "b" 2) "a" 127.0.0.1:6379> llen list (integer) 2 127.0.0.1:6379> # lrem 移除 127.0.0.1:6379> lrange list 0 -1 1) "c" 2) "b" 3) "a" 127.0.0.1:6379> lrem list 1 a #移除list集合中指定个数的value，精确匹配 (integer) 1 127.0.0.1:6379> lrange list 0 -1 1) "c" 2) "b" 127.0.0.1:6379> # ltrim 修剪 127.0.0.1:6379> lrange list 0 -1 1) "hello3" 2) "hello2" 3) "hello1" 4) "hello" 127.0.0.1:6379> ltrim list 1 2 #通过下标截取指定的长度，注：此时list的value已被改变，只剩下截取的元素 OK 127.0.0.1:6379> lrange list 0 -1 1) "hello2" 2) "hello1" 127.0.0.1:6379> # rpoplpush 移除列表的最后一个元素，并将它移动到新的列表中 127.0.0.1:6379> lrange list 0 -1 1) "hello3" 2) "hello2" 3) "hello1" 4) "hello" 127.0.0.1:6379> rpoplpush list otherlist "hello" 127.0.0.1:6379> lrange list 0 -1 1) "hello3" 2) "hello2" 3) "hello1" 127.0.0.1:6379> lrange otherlist 0 -1 1) "hello" 127.0.0.1:6379> # lset 将列表中指定下标的值替换为另一个值（更新） 127.0.0.1:6379> exists list #先判断列表是否存在 (integer) 0 127.0.0.1:6379> lset list 0 hello #如果列表不存在，则会报错 (error) ERR no such key 127.0.0.1:6379> lpush list hello (integer) 1 127.0.0.1:6379> lrange list 0 -1 1) "hello" 127.0.0.1:6379> lset list 0 nihao #如果存在，更新当前下标的值 OK 127.0.0.1:6379> lrange list 0 -1 1) "nihao" 127.0.0.1:6379> lset list 1 xiexie #如果要更新值的下标不存在，则报错 (error) ERR index out of range 127.0.0.1:6379> # linsert 将具体的值插入到列表中某个元素的前面或后面 127.0.0.1:6379> lrange list 0 -1 1) "hello" 2) "world" 127.0.0.1:6379> linsert list before world sunxiaochuan (integer) 3 127.0.0.1:6379> lrange list 0 -1 1) "hello" 2) "sunxiaochuan" 3) "world" 127.0.0.1:6379> linsert list after world liubo (integer) 4 127.0.0.1:6379> lrange list 0 -1 1) "hello" 2) "sunxiaochuan" 3) "world" 4) "liubo" 127.0.0.1:6379>

Redis基本数据类型String String127.0.0.1:6379> set name sunxiaochuan OK 127.0.0.1:6379> get name "sunxiaochuan" 127.0.0.1:6379> append name ",chouxiang" #追加字符串，如果当前字符串不存在，就相当于set key (integer) 22 127.0.0.1:6379> get name "sunxiaochuan,chouxiang" 127.0.0.1:6379> strlen name #获取字符串长度 (integer) 22 #自增 i++ #步长 i+= 127.0.0.1:6379> incr views #自增1 (integer) 1 127.0.0.1:6379> incr views (integer) 2 127.0.0.1:6379> decr views (integer) 1 127.0.0.1:6379> decr views (integer) 0 127.0.0.1:6379> decr views (integer) -1 127.0.0.1:6379> decrby views 5 #设置步长 (integer) -6 127.0.0.1:6379> incrby views 10 (integer) 4 127.0.0.1:6379> #字符串范围 range 127.0.0.1:6379> set test "hello world" OK 127.0.0.1:6379> get test "hello world" 127.0.0.1:6379> getrange test 0 5 #截取字符串[0,5] "hello " 127.0.0.1:6379> 127.0.0.1:6379> getrange test 0 -1 #获取全部字符串 "hello world" 127.0.0.1:6379> #替换 127.0.0.1:6379> set name sunxiaochuan OK 127.0.0.1:6379> get name "sunxiaochuan" 127.0.0.1:6379> setrange name 1 abc #替换指定位置开始的字符串 (integer) 12 127.0.0.1:6379> get name "sabciaochuan" 127.0.0.1:6379> #setex(set with expire) #设置过期时间 #setnx(set if not exist) #如果不存在，设置值为xxx 127.0.0.1:6379> setex name 10 "liubo" #设置name的值为liubo，10秒后过期 OK 127.0.0.1:6379> ttl name (integer) 7 127.0.0.1:6379> get name (nil) 127.0.0.1:6379> setnx name01 "sun" #如果name01不存在，则创建 (integer) 1 127.0.0.1:6379> keys * 1) "name01" 127.0.0.1:6379> setnx name01 "liu" #name01已存在，再次创建时失败 (integer) 0 127.0.0.1:6379> get name01 "sun" 127.0.0.1:6379> 127.0.0.1:6379> mset A a B b C c #同时设置多个值 OK 127.0.0.1:6379> keys * 1) "B" 2) "A" 3) "C" 127.0.0.1:6379> mget A B C #同时获取多个值 1) "a" 2) "b" 3) "c" 127.0.0.1:6379> msetnx A a D d #msetnx是一个原子性操作，要么都成功，要么都失败 (integer) 0 127.0.0.1:6379> get D (nil) 127.0.0.1:6379> #对象 #设置一个id为1的对象，json字符串来保存属性，方式一 127.0.0.1:6379> set user:1 {name:ceshi,age:3} #方式二 user:{id}:{filed} 127.0.0.1:6379> mset user:1:name ceshi user:1:age 3 OK 127.0.0.1:6379> mget user:1:name user:1:age 1) "ceshi" 2) "3" 127.0.0.1:6379> #getset 先get再set 127.0.0.1:6379> getset name sunxiaochuan #如果不存在值，返回null (nil) 127.0.0.1:6379> get name "sunxiaochuan" 127.0.0.1:6379> getset name liubo #如果存在值，获取原来的值，并设置新的值 "sunxiaochuan" 127.0.0.1:6379> get name "liubo" 127.0.0.1:6379> String除了以上用法，还可以用于计数器，多单位数量统计等。

动态SQL 动态SQL==根据不同的条件生成不同的SQL语句==ifchoose (when, otherwise)trim (where, set)foreach搭建环境CREATE TABLE `blog`( `id` VARCHAR(50) NOT NULL COMMENT 'id', `title` VARCHAR(100) NOT NULL COMMENT '标题', `author` VARCHAR(50) NOT NULL COMMENT '作者', `create_time` datetime NOT NULL COMMENT '创建时间', `views` int(11) NOT NULL COMMENT '浏览量' )ENGINE=INNODB DEFAULT CHARSET=utf8;1、导包2、编写配置文件3、创建实体类package com.sw.pojo; import lombok.Data; import java.io.Serializable; import java.util.Date; /** * @Author suaxi * @Date 2020/12/13 16:20 */ @Data public class blog implements Serializable { private String id; private String title; private String author; private Date createTime; private int views; } 4、编写实体类对应的Mapper接口和Mapper.xml文件IF<select id="findBlogIf" parameterType="map" resultType="Blog"> select * from blog where 1=1 <if test="title != null"> and title = #{title} </if> <if test="author != null"> and author = #{author} </if> </select>chose(when,otherwise)<select id="findBlogChoose" parameterType="map" resultType="Blog"> select * from blog <where> <choose> <when test="title != null"> title = #{title} </when> <when test="author != null"> and author = #{author} </when> <otherwise> and views = #{views} </otherwise> </choose> </where> </select>trim(where,set) <select id="findBlogIf" parameterType="map" resultType="Blog"> select * from blog <where> <if test="title != null"> title = #{title} </if> <if test="author != null"> and author = #{author} </if> </where> </select><update id="UpdateBlog" parameterType="map"> update blog <set> <if test="title != null"> title = #{title}, </if> <if test="author != null"> author = #{author} </if> </set> where id = #{id} </update>SQL片段将部分SQl抽取出来，方便复用1、使用SQL标签抽取公共部分<sql id="if-title-author"> <if test="title != null"> title = #{title} </if> <if test="author != null"> and author = #{author} </if> </sql>2、在需要使用的地方用include标签引用、<select id="findBlogIf" parameterType="map" resultType="Blog"> select * from blog <where> <include refid="if-title-author"></include> </where> </select>注：最好基于单表查询，不要存在where标签Foreach<!--select * from bolg where 1=1 and (id=1 or id=2 or id=3)--> <select id="findBlogForeach" parameterType="map" resultType="Blog"> select * from blog <where> <foreach collection="ids" item="id" open="and (" close=")" separator="or"> id = #{id} </foreach> </where> </select>==动态SQL就是在拼接SQL语句，先确保SQL的正确性，再按照SQL格式去排列组合==先在MySQL中写出完整的sql，再去修改成动态sql实现通用

SQL注入 SQL注入sql存在漏洞，会被攻击导致数据泄露,SQL会被拼接 orimport com.sw.kuangshen.utils.JdbcUtils; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; /** * @Author suaxi * @Date 2020/11/9 9:57 */ public class SQlzhuru { public static void main(String[] args) { //login("sunxiaochuan","12345");正常登录 login(" 'or '1=1"," 'or '1=1"); //技巧 } //登录 public static void login(String username,String passwd){ Connection conn = null; Statement st = null; ResultSet rs =null; try { conn = JdbcUtils.getConnection(); //获取数据库连接 st = conn.createStatement(); //获得SQL的执行对象 //SELECT * FROM users WHERE `name`='sunxiaochuan' AND `passwd`='12345'; //SELECT * FROM users WHERE `name`='' or '1=1' AND `passwd`='' or '1=1'; String sql = "SELECT * FROM users WHERE `name`='"+username+"' AND `passwd`='"+passwd+"'"; rs = st.executeQuery(sql); //查询完毕会返回一个结果集 while (rs.next()){ System.out.println(rs.getString("name")); System.out.println(rs.getString("passwd")); System.out.println("================="); } } catch (SQLException e) { e.printStackTrace(); }finally { JdbcUtils.release(conn,st,rs); } } }

PreparedStatement对象 可以防止SQL注入，效率更好。1、新增package com.sw.kuangshen.lesson03; import com.sw.kuangshen.utils.JdbcUtils; import java.sql.Connection; import java.util.Date; import java.sql.PreparedStatement; import java.sql.SQLException; /** * @Author suaxi * @Date 2020/11/9 10:12 */ public class TestInsert { public static void main(String[] args) { Connection conn = null; PreparedStatement pstm = null; try { conn = JdbcUtils.getConnection(); //PreparedStatement与Statement的区别 //使用？占位符代替参数 String sql = "insert into users(id,name,passwd,email,birthday) values(?,?,?,?,?)"; pstm = conn.prepareStatement(sql); //预编译SQl，先编译sql但不执行 //手动给参数赋值 pstm.setInt(1,5); pstm.setString(2,"liubo"); pstm.setString(3,"12345"); pstm.setString(4,"liubo@qq.com"); //注：sql.Date 数据库使用 java.sql.Date() // util.Date Java new Date().getTime() 获得当前时间戳 pstm.setDate(5,new java.sql.Date(new Date().getTime())); //执行 int i = pstm.executeUpdate(); if(i>0){ System.out.println("插入成功！"); } } catch (SQLException e) { e.printStackTrace(); }finally { JdbcUtils.release(conn,pstm,null); } } } 2、删除package com.sw.kuangshen.lesson03; import com.sw.kuangshen.utils.JdbcUtils; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.SQLException; import java.util.Date; /** * @Author suaxi * @Date 2020/11/9 10:28 */ public class TestDelete { public static void main(String[] args) { Connection conn = null; PreparedStatement pstm = null; try { conn = JdbcUtils.getConnection(); //PreparedStatement与Statement的区别 //使用？占位符代替参数 String sql = "delete from users where id=?"; pstm = conn.prepareStatement(sql); //预编译SQl，先编译sql但不执行 //手动给参数赋值 pstm.setInt(1,5); //执行 int i = pstm.executeUpdate(); if(i>0){ System.out.println("删除成功！"); } } catch (SQLException e) { e.printStackTrace(); }finally { JdbcUtils.release(conn,pstm,null); } } } 3、修改package com.sw.kuangshen.lesson03; import com.sw.kuangshen.utils.JdbcUtils; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.SQLException; import java.util.Date; /** * @Author suaxi * @Date 2020/11/9 10:28 */ public class TestUpdate { public static void main(String[] args) { Connection conn = null; PreparedStatement pstm = null; try { conn = JdbcUtils.getConnection(); //PreparedStatement与Statement的区别 //使用？占位符代替参数 String sql = "update users set `name`=? where id=?"; pstm = conn.prepareStatement(sql); //预编译SQl，先编译sql但不执行 //手动给参数赋值 pstm.setString(1,"孙笑川"); pstm.setInt(2,2); //执行 int i = pstm.executeUpdate(); if(i>0){ System.out.println("更新成功！"); } } catch (SQLException e) { e.printStackTrace(); }finally { JdbcUtils.release(conn,pstm,null); } } } 4、查询package com.sw.kuangshen.lesson03; import com.sw.kuangshen.utils.JdbcUtils; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; /** * @Author suaxi * @Date 2020/11/9 10:34 */ public class TestSelect { public static void main(String[] args) { Connection conn = null; PreparedStatement pstm = null; ResultSet rs = null; try { conn = JdbcUtils.getConnection(); String sql = "select * from users where id=?"; pstm = conn.prepareStatement(sql); //预编译 pstm.setInt(1,2); //传递参数 rs = pstm.executeQuery(); //执行 if (rs.next()){ System.out.println(rs.getString("name")); } } catch (SQLException e) { e.printStackTrace(); }finally { JdbcUtils.release(conn,pstm,rs); } } } 5、防止SQL注入package com.sw.kuangshen.lesson03; import com.sw.kuangshen.utils.JdbcUtils; import java.sql.*; /** * @Author suaxi * @Date 2020/11/9 9:57 */ public class SQlzhuru { public static void main(String[] args) { //login("dd","12345"); //正常登录 login("''or 1=1","12345"); } //登录 public static void login(String username,String passwd){ Connection conn = null; PreparedStatement pstm = null; ResultSet rs =null; try { conn = JdbcUtils.getConnection(); //PreparedStatement防止SQL注入的本质，把传递进来的参数当作字符 //假设其中存在转义字符，例如 ' 会被直接转义 String sql = "select * from users where `name`=? and passwd=?"; pstm = conn.prepareStatement(sql); pstm.setString(1,username); pstm.setString(2,passwd); rs = pstm.executeQuery(); while (rs.next()){ System.out.println(rs.getString("name")); System.out.println(rs.getString("passwd")); System.out.println("================="); } } catch (SQLException e) { e.printStackTrace(); }finally { JdbcUtils.release(conn,pstm,rs); } } }