springboot+mybatis+mysql实现crud

注意
1、maven配置好镜像
2、jdk1.8
3、mysql

创建springboot项目

项目结构

需要的依赖pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.jack</groupId>
    <artifactId>springboot-mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-mybatis</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--导入所需要的数据库连接依赖mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.1</version>
        </dependency>
        <!--该依赖提供三个功能
        1、对数据源的装配
        2、提供一个JdbcTemplate简化使用
        3、事务处理-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!--springboot整合mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!-- MySQL 连接驱动依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.22</version>
        </dependency>
        <!--简化实体类-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--数据库mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.22</version>
        </dependency>
        <!--进行单元测试-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.28</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <configuration>
                    <verbose>true</verbose>
                    <overwrite>true</overwrite>
                </configuration>
            </plugin>
            <!--该插件主要是maven之mybatis代码生成器-->
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.2</version>
                <dependencies>
                    <dependency>
                        <groupId>mysql</groupId>
                        <artifactId>mysql-connector-java</artifactId>
                        <version>8.0.22</version>
                    </dependency>
                </dependencies>
                <configuration>
                    <overwrite>true</overwrite>
                </configuration>
            </plugin>
        </plugins>
        <!--以下操作用来扫描resources里面xml文件，默认只能扫描dao层里面-->
        <!-- 如果不添加此节点mybatis的mapper.xml文件都会被漏掉。 -->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.yml</include>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.yml</include>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>

</project>

主启动类

package com.jack.springbootmybatis;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan("com.jack.springbootmybatis.dao")
@SpringBootApplication
public class SpringbootMybatisApplication {
    
    

	public static void main(String[] args) {
    
    
		SpringApplication.run(SpringbootMybatisApplication.class, args);
	}

}

需要的实体类

public class Student {
    
    
    private String stuNo;

    private String stuName;

    private Date stuBornDate;

    private String stuSex;

    public String getStuNo() {
    
    
        return stuNo;
    }

    public void setStuNo(String stuNo) {
    
    
        this.stuNo = stuNo == null ? null : stuNo.trim();
    }

    public String getStuName() {
    
    
        return stuName;
    }

    public void setStuName(String stuName) {
    
    
        this.stuName = stuName == null ? null : stuName.trim();
    }

    public Date getStuBornDate() {
    
    
        return stuBornDate;
    }

    public void setStuBornDate(Date stuBornDate) {
    
    
        this.stuBornDate = stuBornDate;
    }

    public String getStuSex() {
    
    
        return stuSex;
    }

    public void setStuSex(String stuSex) {
    
    
        this.stuSex = stuSex == null ? null : stuSex.trim();
    }

    @Override
    public String toString() {
    
    
        return "Student{" +
                "stuNo='" + stuNo + '\'' +
                ", stuName='" + stuName + '\'' +
                ", stuBornDate=" + stuBornDate +
                ", stuSex='" + stuSex + '\'' +
                '}';
    }
}

对应数据层

package com.jack.springbootmybatis.dao;

import com.jack.springbootmybatis.pojo.Student;

import java.util.List;

public interface StudentMapper {
    
    
    /**
     * @description 根据主键删除
     * @param stuNo 学号
     * @return 受影响行数
     */
    int deleteByPrimaryKey(String stuNo);

    int insert(Student record);

    int insertSelective(Student record);

    /**
     * @description 根据学号查询学生信息
     * @param stuNo 学号
     * @return 该学生信息
     */
    Student selectByPrimaryKey(String stuNo);

    /**
     * @description 多条件查询学生信息
     * @param student 学生信息
     * @return 若是参数为null,全表查询，否则多条件查询
     */
    List<Student> selectSelective(Student student);

    /**
     * @description 不同性别不同学生信息
     * @param student
     * @return
     */
    List<Student> selectSelectiveSex(Student student);



    int updateByPrimaryKeySelective(Student record);

    int updateByPrimaryKey(Student record);
}

对应的视图层

package com.jack.springbootmybatis.controller;

import com.alibaba.fastjson.JSONObject;
import com.jack.springbootmybatis.dao.StudentMapper;
import com.jack.springbootmybatis.pojo.Student;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.List;

@RestController
@RequestMapping("/student")
public class StudentController {
    
    
  @Resource
  private StudentMapper studentMapper ;

  /**
   * 通过@PathVariable占位符方式传参
   */
  @RequestMapping("/selectByPrimaryKey/{stuNo}")
  public Student selectByPrimaryKey(@PathVariable String stuNo){
    
    
    return studentMapper.selectByPrimaryKey(stuNo);
  }

  /**
   * 通过@RequestParam
   */
  @GetMapping("/selectByPrimaryKey1")
  public Student selectByPrimaryKey1(@RequestParam("s1") String stuNo){
    
    
    return studentMapper.selectByPrimaryKey(stuNo);
  }

  @GetMapping("/selectByPrimaryKey2")
  public Student selectByPrimaryKey2(@RequestBody String stuNo) {
    
    
    // 使用fastjson解析json格式字符串为json对象
    JSONObject jsonObject = JSONObject.parseObject(stuNo);
    // 获取学号
    String stuNo1 = jsonObject.getString("stuNo");
    return studentMapper.selectByPrimaryKey(stuNo1);
  }

  @GetMapping("/selectSelective")
  public List<Student> selectSelective(@RequestBody Student student){
    
    
    return studentMapper.selectSelective(student);
  }

  @GetMapping("/selectSelectiveSex")
  public List<Student> selectSelectiveSex(@RequestBody Student student){
    
    
    return studentMapper.selectSelectiveSex(student);
  }
}

对应的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.jack.springbootmybatis.dao.StudentMapper" >
  <resultMap id="BaseResultMap" type="com.jack.springbootmybatis.pojo.Student" >
    <id column="stu_no" property="stuNo" jdbcType="VARCHAR" />
    <result column="stu_name" property="stuName" jdbcType="VARCHAR" />
    <result column="stu_born_date" property="stuBornDate" jdbcType="DATE" />
    <result column="stu_sex" property="stuSex" jdbcType="CHAR" />
  </resultMap>
  <sql id="Base_Column_List" >
    stu_no, stu_name, stu_born_date, stu_sex
  </sql>
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.String" >
    select 
    <include refid="Base_Column_List" />
    from student
    where stu_no = #{stuNo,jdbcType=VARCHAR}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.String" >
    delete from student
    where stu_no = #{stuNo,jdbcType=VARCHAR}
  </delete>
  <insert id="insert" parameterType="com.jack.springbootmybatis.pojo.Student" >
    insert into student (stu_no, stu_name, stu_born_date, 
      stu_sex)
    values (#{stuNo,jdbcType=VARCHAR}, #{stuName,jdbcType=VARCHAR}, #{stuBornDate,jdbcType=DATE}, 
      #{stuSex,jdbcType=CHAR})
  </insert>
  <insert id="insertSelective" parameterType="com.jack.springbootmybatis.pojo.Student" >
    insert into student
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="stuNo != null" >
        stu_no,
      </if>
      <if test="stuName != null" >
        stu_name,
      </if>
      <if test="stuBornDate != null" >
        stu_born_date,
      </if>
      <if test="stuSex != null" >
        stu_sex,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="stuNo != null" >
        #{stuNo,jdbcType=VARCHAR},
      </if>
      <if test="stuName != null" >
        #{stuName,jdbcType=VARCHAR},
      </if>
      <if test="stuBornDate != null" >
        #{stuBornDate,jdbcType=DATE},
      </if>
      <if test="stuSex != null" >
        #{stuSex,jdbcType=CHAR},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.jack.springbootmybatis.pojo.Student" >
    update student
    <set >
      <if test="stuName != null" >
        stu_name = #{stuName,jdbcType=VARCHAR},
      </if>
      <if test="stuBornDate != null" >
        stu_born_date = #{stuBornDate,jdbcType=DATE},
      </if>
      <if test="stuSex != null" >
        stu_sex = #{stuSex,jdbcType=CHAR},
      </if>
    </set>
    where stu_no = #{stuNo,jdbcType=VARCHAR}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.jack.springbootmybatis.pojo.Student" >
    update student
    set stu_name = #{stuName,jdbcType=VARCHAR},
      stu_born_date = #{stuBornDate,jdbcType=DATE},
      stu_sex = #{stuSex,jdbcType=CHAR}
    where stu_no = #{stuNo,jdbcType=VARCHAR}
  </update>
  <select id="selectSelective" resultMap="BaseResultMap" parameterType="com.jack.springbootmybatis.pojo.Student">
    select
    <include refid="Base_Column_List" />
    from student
    <where>
      <if test="stuNo != null and stuNo != ''">
        stu_no=${stuNo}
      </if>
      <if test="stuName != null and stuName != ''">
        stu_name=${stuName}
      </if>
      <if test="stuBornDate != null and stuBornDate != ''">
        stu_born_date=${stuBornDate}
      </if>
      <if test="stuSex != null and stuSex != ''">
        stu_sex=${stuSex}
      </if>
    </where>
  </select>
  <select id="selectSelectiveSex" resultMap="BaseResultMap" parameterType="com.jack.springbootmybatis.pojo.Student">
    select
    <include refid="Base_Column_List" />
    from student
    <where>
      <choose>
        <when test="stuSex != null ">
            stu_sex = #{stuSex}
        </when> <when test="stuName != null ">
            stu_name = #{stuName}
        </when>

        <otherwise>
          stu_sex = "中"
        </otherwise>
      </choose>
    </where>
  </select>
</mapper> 

数据库配置文件

server:
  port: 8080 # 服务端口号

spring:
  datasource:
    username: root # mysql用户名
    password: root # mysql密码
    url: jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
    driver-class-name: com.mysql.cj.jdbc.Driver # mysql8.0版本

mybatis:
  mapper-locations: classpath:mapper/*Mapper.xml # 扫描mapper文件xml
  type-aliases-package: com.jack.springbootmybatis.pojo # 别名映射

# 控制台显示SQL语句
logging:
  level:
    com:
      jack:
        springbootmybatis:
          dao : debug

postman调用测试