Springboot（十五）整合mybatis

程序员文章站 2022-05-29 17:49:05

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新建一个springboot工程，pom.xml中引入下面依赖包：

<?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>com.xhx.springboot</groupId>
    <artifactId>springboot6</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot6</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

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

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

application.yml文件：加入数据库配置和mybatis的配置

spring:
  datasource:
    username: xuhaixing
    password: xuhaixing
    url: jdbc:mysql://192.168.94.151:3306/mytest?useUnicode=true&characterEncoding=utf8&characterSetResults=utf8
    driver-class-name: com.mysql.jdbc.Driver
mybatis:
  mapper-locations: classpath:mybatis/mapping/*.xml
  type-aliases-package: com.xhx.springboot.entity
  config-location: classpath:mybatis/mybatis-config.xml

mybatis-config.xml

<?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>
    <!-- 全局参数 -->
    <settings>
        <!-- 使全局的映射器启用或禁用缓存。 -->
        <setting name="cacheEnabled" value="true"/>

        <!-- 全局启用或禁用延迟加载。当禁用时，所有关联对象都会即时加载。 -->
        <setting name="lazyLoadingEnabled" value="true"/>

        <!-- 当启用时，有延迟加载属性的对象在被调用时将会完全加载任意属性。否则，每种属性将会按需要加载。 -->
        <setting name="aggressiveLazyLoading" value="true"/>

        <!-- 是否允许单条sql 返回多个数据集  (取决于驱动的兼容性) default:true -->
        <setting name="multipleResultSetsEnabled" value="true"/>

        <!-- 是否可以使用列的别名 (取决于驱动的兼容性) default:true -->
        <setting name="useColumnLabel" value="true"/>

        <!-- 允许JDBC 生成主键。需要驱动器支持。如果设为了true，这个设置将强制使用被生成的主键，有一些驱动器不兼容不过仍然可以执行。  default:false  -->
        <setting name="useGeneratedKeys" value="false"/>

        <!-- 指定 MyBatis 如何自动映射 数据基表的列 NONE：不隐射　PARTIAL:部分  FULL:全部  -->
        <setting name="autoMappingBehavior" value="PARTIAL"/>

        <!-- 这是默认的执行类型  （SIMPLE: 简单； REUSE: 执行器可能重复使用prepared statements语句；BATCH: 执行器可以重复执行语句和批量更新）  -->
        <setting name="defaultExecutorType" value="SIMPLE"/>

        <!-- 使用驼峰命名法转换字段。 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>

        <!-- 设置本地缓存范围 session:就会有数据的共享  statement:语句范围 (这样就不会有数据的共享 ) defalut:session -->
        <setting name="localCacheScope" value="SESSION"/>

        <!-- 设置但JDBC类型为空时,某些驱动程序 要指定值,default:OTHER，插入空值时不需要指定类型 -->
        <setting name="jdbcTypeForNull" value="NULL"/>

        <!-- 打印查询语句 -->
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>

    <typeAliases>
        <typeAlias alias="Integer" type="java.lang.Integer"/>
        <typeAlias alias="Long" type="java.lang.Long"/>
        <typeAlias alias="HashMap" type="java.util.HashMap"/>
        <typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap"/>
        <typeAlias alias="ArrayList" type="java.util.ArrayList"/>
        <typeAlias alias="LinkedList" type="java.util.LinkedList"/>
    </typeAliases>

    <mappers>
    </mappers>
</configuration>

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.xhx.springboot.mapper2.AccountMapper2">
    <resultMap id="BaseResultMap" type="com.xhx.springboot.entity.Account">
        <id column="id" jdbcType="INTEGER" property="id"/>
        <result column="name" jdbcType="VARCHAR" property="name"/>
        <result column="money" jdbcType="DOUBLE" property="money"/>
    </resultMap>
    <sql id="Base_Column_List">
        id, name, money
    </sql>
    <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_List"/>
        from account
        where id = #{id,jdbcType=INTEGER}
    </select>
    <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
        delete from account
        where id = #{id,jdbcType=INTEGER}
    </delete>
    <insert id="insert" parameterType="com.xhx.springboot.entity.Account">
        insert into account (id, name, money
        )
        values (#{id,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR}, #{money,jdbcType=DOUBLE}
        )
    </insert>
    <insert id="insertSelective" parameterType="com.xhx.springboot.entity.Account">
        insert into account
        <trim prefix="(" suffix=")" suffixOverrides=",">
            <if test="id != null">
                id,
            </if>
            <if test="name != null">
                name,
            </if>
            <if test="money != null">
                money,
            </if>
        </trim>
        <trim prefix="values (" suffix=")" suffixOverrides=",">
            <if test="id != null">
                #{id,jdbcType=INTEGER},
            </if>
            <if test="name != null">
                #{name,jdbcType=VARCHAR},
            </if>
            <if test="money != null">
                #{money,jdbcType=DOUBLE},
            </if>
        </trim>
    </insert>
    <update id="updateByPrimaryKeySelective" parameterType="com.xhx.springboot.entity.Account">
        update account
        <set>
            <if test="name != null">
                name = #{name,jdbcType=VARCHAR},
            </if>
            <if test="money != null">
                money = #{money,jdbcType=DOUBLE},
            </if>
        </set>
        where id = #{id,jdbcType=INTEGER}
    </update>
    <update id="updateByPrimaryKey" parameterType="com.xhx.springboot.entity.Account">
        update account
        set name = #{name,jdbcType=VARCHAR},
        money = #{money,jdbcType=DOUBLE}
        where id = #{id,jdbcType=INTEGER}
    </update>
</mapper>

mapper类

package com.xhx.springboot.mapper2;

import com.xhx.springboot.entity.Account;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface AccountMapper2 {
    int deleteByPrimaryKey(Integer id);

    int insert(Account record);

    int insertSelective(Account record);

    Account selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(Account record);

    int updateByPrimaryKey(Account record);
}

也可以用mybatis注解：

package com.xhx.springboot.mapper;

import com.xhx.springboot.entity.Account;
import org.apache.ibatis.annotations.*;

import java.util.List;

@Mapper
public interface AccountMapper {
    @Insert("insert into account(name, money) values(#{name}, #{money})")
    int add(@Param("name") String name, @Param("money") double money);

    @Update("update account set name = #{name}, money = #{money} where id = #{id}")
    int update(@Param("name") String name, @Param("money") double money, @Param("id") int id);

    @Delete("delete from account where id = #{id}")
    int delete(int id);

    @Select("select id, name as name, money as money from account where id = #{id}")
    Account findAccount(@Param("id") int id);

    @Select("select id, name as name, money as money from account")
    List<Account> findAccountList();
}

我的工程目录

Springboot（十五）整合mybatis