Mybatis使用配置（3、增删改查curd）

最新推荐文章于 2025-03-26 18:59:48 发布

:️

最新推荐文章于 2025-03-26 18:59:48 发布

阅读量190

点赞数

分类专栏：框架及模板文章标签： java xml intellij-idea

本文链接：https://blog.youkuaiyun.com/weixin_43767429/article/details/125242194

版权

框架及模板专栏收录该内容

7 篇文章

订阅专栏

本文详细介绍了如何在Maven工程中配置MyBatis进行数据库操作，包括pom.xml文件的依赖配置，mybatis-config.xml的数据库连接设置，以及logback.xml的日志配置。此外，还展示了Brand实体类、BrandMapper接口及其xml实现，包括增删改查等基本操作。最后，提供了测试类展示了如何使用MyBatis进行数据操作。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Mybatis使用配置（已完成curd）：

项目结构（maven工程）：

在这里插入图片描述

一、配置相关

pom文件

提示：引入的模块

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>mybatis-crud</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.5</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>

        <!-- 添加slf4j日志api -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.20</version>
        </dependency>
        <!-- 添加logback-classic依赖 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
        <!-- 添加logback-core依赖 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
            <version>1.2.3</version>
        </dependency>

    </dependencies>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

</project>

mybatis-config.xml：

提示：数据库链接配置及xml文件配置

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <typeAliases>
        <!--这个配置使得UserMapper.xml的resultType可以直接写类名Brand-->
        <package name="com.niujl.pojo"/>
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <!--                链接信息-->
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///mybatis?useSSL=false"/>
                <property name="username" value="root"/>
                <property name="password" value="admin"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!--        加载sql的映射文件-->
        <!--        <mapper resource="com/niujl/mapper/UserMapper.xml"/>-->
        <package name="com.niujl.mapper"/>

    </mappers>
</configuration>

logback.xml：

提示：控制台输出

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <!--
        CONSOLE ：表示当前的日志信息是可以输出到控制台的。
    -->
    <appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>[%level] %blue(%d{HH:mm:ss.SSS}) %cyan([%thread]) %boldGreen(%logger{15}) - %msg %n</pattern>
        </encoder>
    </appender>

    <logger name="com.itheima" level="DEBUG" additivity="false">
        <appender-ref ref="Console"/>
    </logger>


    <!--

      level:用来设置打印级别，大小写无关：TRACE, DEBUG, INFO, WARN, ERROR, ALL 和 OFF
     ， 默认debug
      <root>可以包含零个或多个<appender-ref>元素，标识这个输出位置将会被本日志级别控制。
      -->
    <root level="DEBUG">
        <appender-ref ref="Console"/>
    </root>
</configuration>

二、业务逻辑

定义实体类（Brand）

package com.niujl.pojo;

public class Brand {
    // id 主键
    private Integer id;
    // 品牌名称
    private String brandName;
    // 企业名称
    private String companyName;
    // 排序字段
    private Integer ordered;
    // 描述信息
    private String description;
    // 状态：0：禁用  1：启用
    private Integer status;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getBrandName() {
        return brandName;
    }

    public void setBrandName(String brandName) {
        this.brandName = brandName;
    }

    public String getCompanyName() {
        return companyName;
    }

    public void setCompanyName(String companyName) {
        this.companyName = companyName;
    }

    public Integer getOrdered() {
        return ordered;
    }

    public void setOrdered(Integer ordered) {
        this.ordered = ordered;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    @Override
    public String toString() {
        return "Brand{" +
                "id=" + id +
                ", brandName='" + brandName + '\'' +
                ", companyName='" + companyName + '\'' +
                ", ordered=" + ordered +
                ", description='" + description + '\'' +
                ", status=" + status +
                '}';
    }
}

定义接口方法（BrandMapper.java）

package com.niujl.mapper;

import com.niujl.pojo.Brand;
import org.apache.ibatis.annotations.Param;

import java.util.List;
import java.util.Map;

public interface BrandMapper {
    /**
     * 查询所有
     * @return
     */
    List<Brand> selectAll();
    /**
     * 查看详情：根据id
     */
    List<Brand> selectById(int id);
    /**
     * 根据条件查找
     * 1、散装参数：
     * 2、对象参数：
     * 3、map集合参数：
     */
//    @Param()注解是给xml(写sql语句的文件代码看的)，因为sql语句有多个参数占位符，所以需要指定参数占位符与值的对应关系
//    List<Brand> selectByCondition(@Param("status") int status, @Param("companyName") String companyName, @Param("brandName")String brandName);
//    如果传的是对象的话
//    List<Brand> selectByCondition(Brand brand);
//    如果传的是Map集合的话
    List<Brand> selectByCondition(Map map);
    /**
     * 单条件动态查询
     */
    List<Brand> selectByConditionSingle(Brand brand);
    /**
     * 添加记录
     */
    void add(Brand brand);
    /**
     * 修改功能
     */
    int update(Brand brand);
    /**
     * 根据id删除功能
     */
    void deleteById(int id);
    /**
     * 批量删除
     * 数组需要注解改变一下传递的名称
     * mybatis会将数组封装成一个map集合
     *               key:array , value:数组
     *               使用@Param注解改变map集合的默认key的名称
     */
    void deleteByIds(@Param("ids") int[] ids );
}

定义对应的实现接口的sql语句（BrandMapper.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">
<!--
    namespace="com.niujl.mapper.UserMapper"：名称空间地址要与定义sql语句的接口UserMapper一致
    id="selectAll"：相当于实现UserMapper接口的方法
-->
<mapper namespace="com.niujl.mapper.BrandMapper">
    <resultMap id="brandResultMap" type="brand">
        <result column="brand_name" property="brandName"/>
        <result column="company_name" property="companyName"/>
    </resultMap>
<!--    查询所有-->
    <select id="selectAll" resultMap="brandResultMap">
        select *
        from tb_brand;
    </select>
<!--    根据id查询所有信息-->
    <select id="selectById" resultMap="brandResultMap">
#         不用${id} 是因为防止sql注入（直接拼接显示）；#{id}这种方式拼接的是'?'，然后参数占位符'?' 替换 为值
        select *
        from tb_brand where id = #{id};
    </select>
    <!--    动态多条件条件查询-->
    <select id="selectByCondition" resultMap="brandResultMap">
        select *
        from tb_brand
        where
            <if test="status != null">
                and status = #{status}
            </if>
            <if test="companyName != null and companyName != ''">
                and company_name like #{companyName}
            </if>
            <if test="brandName != null and brandName != ''">
                and brand_name like #{brandName}
            </if>
    </select>
<!--    单条件动态查询-->
    <select id="selectByConditionSingle" resultMap="brandResultMap">
        select *
        from tb_brand
        <!--where、if 是mybatis提供的动态标签来拼接sql语句-->
        <where>
            <choose>
                <when test="status != null">
                    status = #{status}
                </when>
                <when test="companyName != null and companyName != '' ">
                    company_name like #{companyName}
                </when>
                <when test="brandName != null and brandName != '' ">
                    brand_name like #{brandName}
                </when>
            </choose>
        </where>
    </select>
<!--    完整添加一条记录 设置useGeneratedKeys="true" keyProperty="id"，测试类才可以拿到返回值id-->
    <insert id="add" useGeneratedKeys="true" keyProperty="id">
        insert into tb_brand (brand_name, company_name, ordered, description, status)
        values (#{brandName},#{companyName},#{ordered},#{description},#{status});
    </insert>
<!--    更新一条记录-->
    <update id="update">
        update tb_brand
        <set>
            <if test="brandName != null and brandName != ''">
                brand_name = #{brandName},
            </if>
            <if test="companyName != null and companyName != ''">
                company_name = #{companyName},
            </if>
            <if test="ordered != null">
                ordered = #{ordered},
            </if>
            <if test="description != null and description != ''">
                description = #{description},
            </if>
            <if test="status != null">
                status = #{status}
            </if>
        </set>
        where id = #{id};
    </update>
<!--    根据id删除一条记录-->
    <delete id="deleteById">
        delete
        from tb_brand
        where id=#{id};
    </delete>
<!--    删除多个id对应的记录-->
    <delete id="deleteByIds">
        delete
        from tb_brand
        where id
        in (
            <foreach collection="ids" item="id" separator="," open="(" close=")">
                #{id}
            </foreach>
            );
    </delete>

</mapper>

三、测试类

package com.niujl.test;

import com.niujl.mapper.BrandMapper;
import com.niujl.pojo.Brand;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MyBatisTest {
    @Test
    public void testSelectAll() throws IOException {
        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        3、执行sql
//        List<User> users = sqlSession.selectList("test.selectAll");
//        System.out.println(users);
//        3、1获取UserMapper接口代理的对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
        List<Brand> brands = brandMapper.selectAll();
        System.out.println(brands);
//        4、释放资源
        sqlSession.close();
    }
    @Test
    public void testSelectById() throws IOException {
        //设置参数
        int id=1;

        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        3、1获取UserMapper接口代理的对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//        3、2执行方法
        List<Brand> brands = brandMapper.selectById(id);
        System.out.println(brands);
//        4、释放资源
        sqlSession.close();
    }

    @Test
    public void testSelectByCondition() throws IOException {
        //设置参数
//        int status=1;
        String companyName="华为";
//        String brandName="华为";
        //处理参数
        companyName = "%" + companyName + "%";
//        brandName = "%" + brandName + "%";
        //封装对象
        Brand brand = new Brand();
//        brand.setStatus(status);
        brand.setCompanyName(companyName);
//        brand.setBrandName(brandName);
        //封装成Map
        Map map = new HashMap();
//        map.put("status", status);
        map.put("companyName", companyName);
//        map.put("brandName", brandName);

        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        3、1获取UserMapper接口代理的对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//        3、2执行方法（封装成对象或map来执行最好）（mybatis会解析map或brand对象）
//        List<Brand> brands = brandMapper.selectByCondition(status, companyName, brandName);
//        List<Brand> brands = brandMapper.selectByCondition(brand);
        List<Brand> brands = brandMapper.selectByCondition(map);
        System.out.println(brands);
//        4、释放资源
        sqlSession.close();
    }

    @Test
    public void testSelectByConditionSingle() throws IOException {
        //设置参数
//        int status=1;
        String companyName="小米";
//        String brandName="小米";
        //处理参数
        companyName = "%" + companyName + "%";
//        brandName = "%" + brandName + "%";
        //封装对象
        Brand brand = new Brand();
//        brand.setStatus(status);
        brand.setCompanyName(companyName);
//        brand.setBrandName(brandName);
        //封装Map对象
//        Map map = new HashMap();
//        map.put("status", status);
//        map.put("companyName", companyName);
//        map.put("brandName", brandName);

        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        3、1获取UserMapper接口代理的对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//        3、2执行方法
//        List<Brand> brands = brandMapper.selectByConditionSingle(status, companyName, brandName);
        List<Brand> brands = brandMapper.selectByConditionSingle(brand);
        System.out.println(brands);
//        4、释放资源
        sqlSession.close();
    }

    @Test
    public void testAdd() throws IOException {
        //设置参数
        int status=1;
        String companyName="波导手机";
        String brandName="波导002";
        String description = "手机中的战斗机!";
        int ordered = 100;
        //封装对象
        Brand brand = new Brand();
        brand.setStatus(status);
        brand.setCompanyName(companyName);
        brand.setBrandName(brandName);
        brand.setDescription(description);
        brand.setOrdered(ordered);
        //封装Map对象
//        Map map = new HashMap();
//        map.put("status", status);
//        map.put("companyName", companyName);
//        map.put("brandName", brandName);

        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        2、1是否开启事务（不填则为false-开启事物，需要commit）（flase，则需要commit提交；true，则自动提交）
//        SqlSession sqlSession = sqlSessionFactory.openSession(true);
//        3、1获取UserMapper接口代理的对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//        3、2执行方法，添加记录没有返回值
        brandMapper.add(brand);
//        3、3提交事务才能保存在数据库中（若开启了事务，必须执行commit）;XML里设置useGeneratedKeys="true" keyProperty="id"，才可以拿到返回值id
        sqlSession.commit();
        Integer id = brand.getId();
        System.out.println(id);
//        4、释放资源
        sqlSession.close();
    }

    @Test
    public void testUpdate() throws IOException {
        //设置参数
        int status=0;
//        String companyName="波导手机";
//        String brandName="波导1";
//        String description = "波导手机,手机中的战斗机";
        int ordered = 400;
        int id = 9;
        //封装测试的参数对象
        Brand brand = new Brand();
        brand.setStatus(status);
//        brand.setCompanyName(companyName);
//        brand.setBrandName(brandName);
//        brand.setDescription(description);
        brand.setOrdered(ordered);
        brand.setId(id);
        //封装Map对象
//        Map map = new HashMap();
//        map.put("status", status);
//        map.put("companyName", companyName);
//        map.put("brandName", brandName);

        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        3、1获取UserMapper接口代理的对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//        3、2执行方法，添加记录没有返回值
        int count = brandMapper.update(brand);
//        3、3提交事务才能保存在数据库中（若开启了事务，必须执行commit）
        sqlSession.commit();
        System.out.println(count);
//        4、释放资源
        sqlSession.close();
    }

    @Test
    public void testDeleteById() throws IOException {
        //设置参数
        int id = 10;

        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        3、1获取UserMapper接口代理的对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//        3、2执行方法，删除没有返回值
        brandMapper.deleteById(id);
//        3、3提交事务才能保存在数据库中（若开启了事务，必须执行commit）
        sqlSession.commit();
//        System.out.println(count);
//        4、释放资源
        sqlSession.close();
    }

    @Test
    public void testDeleteByIds() throws IOException {
        //接受参数
        int[] ids = {11,12};

        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        3、1获取UserMapper接口代理的对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//        3、2执行方法，删除没有返回值
        brandMapper.deleteByIds(ids);
//        3、3提交事务才能保存在数据库中（若开启了事务，必须执行commit）
        sqlSession.commit();
//        System.out.println(count);
//        4、释放资源
        sqlSession.close();
    }

}