引入依赖


<dependencies>
    <!-- springmvc的场景启动器 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>2.6.5</version>
    </dependency>

    <!-- MySQL驱动包 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.28</version>
    </dependency>

    <!-- Mybatis的场景启动器 -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.2.2</version>
    </dependency>

    <!-- 单元测试场景启动器 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <version>2.6.5</version>
    </dependency>
</dependencies>


application.yml配置

server:
   #端口号
   port: 9527
 spring:
   #数据库配置
   datasource:
     driver-class-name: com.mysql.cj.jdbc.Driver
     url: jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
     username: root
     password: 123456
 # MyBatis配置
 mybatis:
   mapper-locations: com/thk/mapper/*Mapper.xml


 

实体类:

public class People {
     /**
      * id
      */
     private Long id;
     /**
      * 姓名
      */
     private String name;
     /**
      * 年龄
      */
     private Integer age;
     /**
      * 地址
      */
     private String address;    public Long getId() {
         return id;
     }    public void setId(Long id) {
         this.id = id;
     }    public String getName() {
         return name;
     }    public void setName(String name) {
         this.name = name;
     }    public Integer getAge() {
         return age;
     }    public void setAge(Integer age) {
         this.age = age;
     }    public String getAddress() {
         return address;
     }    public void setAddress(String address) {
         this.address = address;
     }    @Override
     public String toString() {
         return "People{" +
                 "id=" + id +
                 ", name='" + name + '\'' +
                 ", age=" + age +
                 ", address='" + address + '\'' +
                 '}';
     }
     
 }

生成id雪花算法工具类


package com.thk.utils;

/**
 * 分布式唯一ID 雪花算法实现
 */
public class SnowFlake {
    /**
     * 起始的时间戳  
     */
    private final static long START_TIMESTAMP = 1593446400L;

    /**
     * 每一部分占用的位数
     */
    private final static long SEQUENCE_BIT = 12; //序列号占用的位数
    private final static long MACHINE_BIT = 5;   //机器标识占用的位数
    private final static long DATA_CENTER_BIT = 5;//数据中心占用的位数

    /**
     * 每一部分的最大值
     */
    private final static long MAX_DATA_CENTER_NUM = -1L ^ (-1L << DATA_CENTER_BIT);
    private final static long MAX_MACHINE_NUM = -1L ^ (-1L << MACHINE_BIT);
    private final static long MAX_SEQUENCE = -1L ^ (-1L << SEQUENCE_BIT);

    /**
     * 每一部分向左的位移
     */
    private final static long MACHINE_LEFT = SEQUENCE_BIT;
    private final static long DATA_CENTER_LEFT = SEQUENCE_BIT + MACHINE_BIT;
    private final static long TIMESTAMP_LEFT = DATA_CENTER_LEFT + DATA_CENTER_BIT;

    /**
     * 数据中心编码,初始化后不可修改
     * 最大值: 2^5-1 取值范围: [0,31]
     */
    private long dataCenterId;

    /**
     * 机器或进程编码,初始化后不可修改
     * 最大值: 2^5-1 取值范围: [0,31]
     */
    private long machineId;

    /**
     * 序列号
     * 最大值: 2^12-1 取值范围: [0,4095]
     */
    private long sequence = 0L;

    private long lastStamp = -1L;//上一次时间戳

    public SnowFlake(long dataCenterId, long machineId) {
        if (dataCenterId > MAX_DATA_CENTER_NUM || dataCenterId < 0) {
            throw new IllegalArgumentException("dataCenterId can't be greater than MAX_DATA_CENTER_NUM or less than 0");
        }
        if (machineId > MAX_MACHINE_NUM || machineId < 0) {
            throw new IllegalArgumentException("machineId can't be greater than MAX_MACHINE_NUM or less than 0");
        }
        this.dataCenterId = dataCenterId;
        this.machineId = machineId;
    }

    /**
     * 产生下一个ID
     *
     * @return
     */
    public synchronized long nextId() {
        //获取当前时间戳 可用System.currentTimeMillis(); 方法替换
        long currStamp = getNewStamp();
        //保证当前时间戳不小于最后一次的时间戳
        if (currStamp < lastStamp) {
            throw new RuntimeException("Clock moved backwards.  Refusing to generate id");
        }
        //如果当前时间戳等于最后一次时间戳 就进行序号递增
        if (currStamp == lastStamp) {
            //相同毫秒内,序列号自增
            sequence = (sequence + 1) & MAX_SEQUENCE;
            //同一毫秒的序列数已经达到最大
            if (sequence == 0L) {
                currStamp = getNextMill();
            }
        } else {
            //不同毫秒内,序列号置为0
            sequence = 0L;
        }
        //保存最后一次时间戳
        lastStamp = currStamp;
        //通过位运算,将相应的二进制数值放到对应的位置  41位时间戳 + 5位数据中心 + 5位机器码 + 12位序列号 ,首位没有使用
        return (currStamp - START_TIMESTAMP) << TIMESTAMP_LEFT //时间戳部分
                | dataCenterId << DATA_CENTER_LEFT       //数据中心部分
                | machineId << MACHINE_LEFT             //机器标识部分
                | sequence;                             //序列号部分
    }

    private long getNextMill() {
        //获取当前时间戳
        long mill = getNewStamp();
        //获取大于上一次时间戳的时间戳
        while (mill <= lastStamp) {
            mill = getNewStamp();
        }
        return mill;
    }

    /**
     * 获取当前时间戳
     */
    private long getNewStamp() {
        return System.currentTimeMillis();
    }

}


controller


package com.thk.controller;

import com.thk.domain.People;
import com.thk.service.IPeopleService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import javax.websocket.server.PathParam;
import java.util.List;

@RestController
public class PeopleController {
    @Autowired
    private IPeopleService peopleService;

    /**
     * 查询全部用户
     *
     * @param people
     * @return
     */
    @GetMapping("/selectAll")
    public List<People> selectAll(People people) {
        return peopleService.selectAll(people);
    }

    /**
     * 增加用户或者修改用户
     *
     * @param people
     * @return
     */
    @PostMapping("/people")
    public int people(@RequestBody People people) throws Exception {
        return peopleService.people(people);
    }

    /**
     * 根据id查询一条数据
     *
     * @param id
     * @return
     */
    @GetMapping("/selectOne/{id}")
    public People selectOne(@PathVariable Long id) {
        return peopleService.selectOne(id);
    }

    /**
     * 删除数据
     * @param id
     * @return
     */
    @DeleteMapping("/delPeople/{id}")
    public int delPeople(@PathVariable Long id) throws Exception{
        return peopleService.delPeople(id);
    }

}


service


public interface IPeopleService {
    /**
     * 查询全部用户
     *
     * @param people
     * @return
     */
    List<People> selectAll(People people);

    /**
     * 增加用户或者修改用户
     *
     * @param people
     * @return
     */
    int people(People people) throws Exception;

    /**
     * 根据id查询一条数据
     *
     * @param id
     * @return
     */
    People selectOne(Long id);

    /**
     * 删除数据
     * @param id
     * @return
     */
    int delPeople(Long id) throws Exception;
}


service实现类:


@Service
public class PeopleImpl implements IPeopleService {
    @Autowired
    private PeopleMapper peopleMapper;

    /**
     * 查询全部用户
     *
     * @param people
     * @return
     */
    @Override
    public List<People> selectAll(People people) {
        return peopleMapper.selectAll(people);
    }

    /**
     * 增加用户或者修改用户
     *
     * @param people
     * @return
     */
    @Override
    public int people(People people) throws Exception {
        //判断id是否为空,如果为空就是添加
        if (StringUtils.isEmpty(people.getId())) {
            SnowFlake snowFlake = new SnowFlake(2, 3);
            long l = snowFlake.nextId();
            //设置id
            people.setId(l);
            System.out.println("添加的id是" + l);
            //添加数据
            return peopleMapper.addPeople(people);

        } else {
            //如果id不为空,就是修改
            //到数据库查询是否存在这条数据,如果不存在抛出异常
            People people1 = peopleMapper.selectOne(people.getId());
            if (people1 == null) {
                throw new Exception("修改的数据不存在!!!");
            }
            //修改数据
            return peopleMapper.updatePeople(people);
        }
    }

    /**
     * 根据id查询一条数据
     *
     * @param id
     * @return
     */
    @Override
    public People selectOne(Long id) {
        return peopleMapper.selectOne(id);
    }

    /**
     * 删除数据
     *
     * @param id
     * @return
     */
    @Override
    public int delPeople(Long id) throws Exception {
        if (id != null) {
            People people = peopleMapper.selectOne(id);
            if (people != null) {
                //删除数据
                return peopleMapper.delPeople(id);
            } else {
                throw new Exception("修改的数据不存在!!!");
            }
        } else {
            throw new Exception("数据异常!!!");
        }

    }
}


mapper接口


@Mapper
public interface PeopleMapper {
    /**
     * 查询全部用户
     *
     * @param people
     * @return
     */
    List<People> selectAll(People people);

    /**
     * 根据id查询一条数据
     *
     * @param id
     * @return
     */
    People selectOne(Long id);

    /**
     * 添加数据
     *
     * @param people
     * @return
     */
    int addPeople(People people);

    /**
     * 修改数据
     *
     * @param people
     * @return
     */
    int updatePeople(People people);

    /**
     * 删除数据
     *
     * @param id
     * @return
     */
    int delPeople(Long id);
}


mapper.xml


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.thk.mapper.PeopleMapper">
    <!--查询全部数据-->
    <select id="selectAll" resultType="com.thk.domain.People">
        SELECT  * FROM  people
    </select>
    <!--根据id查询一条数据-->
    <select id="selectOne" resultType="com.thk.domain.People">
        SELECT  * FROM  people where  id =#{id}
    </select>
    <!--添加一条数据-->
    <insert id="addPeople">
        insert  into people(id,name,age,address) values (#{id},#{name},#{age},#{address})
    </insert>
    <!--修改数据-->
    <update id="updatePeople">
        update people
        <trim prefix="SET" suffixOverrides=",">
            <if test="name != null and name != ''">name = #{name},</if>
            <if test="age != null">age = #{age},</if>
            <if test="address != null and address != ''">address = #{address},</if>
        </trim>
        where id = #{id}
    </update>
    <!--删除数据-->
    <delete id="delPeople">
         delete from
        people
        where id =#{id}
    </delete>
</mapper>


启动程序:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_数据

测试添加数据

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_时间戳_02

运行结果:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_数据_03

日志打印:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_spring_04

测试修改数据:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_spring_05

 运行结果:

原数据:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_数据_03

修改后:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_java_07

 日志打印:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_数据_08

测试查询一条数据

运行结果:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_时间戳_09

 删除数据

运行结果:

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_时间戳_10

打印日志

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_数据_11

查询全部数据,发现添加的数据已经被删除了

springdataredis CrudRepository 如何自定义查询删除 增删改查springboot_spring_12

以上就是数据库单表额CRUD