Spring整合MyBatis

一、Dao层接口

1、在Dao文件夹下面建立SeckillDao文件，代码如下：

public interface SeckillDao {
    //秒杀减库存
    int updateSeckillById(@Param("Id") Integer Id,@Param("killtime") Date killtime);

    //查询单条信息
    Seckill qurryById(Integer Id);

    //查询所有秒杀列表
    List<Seckill> qurryAll(@Param("offet") Integer offet,@Param("Limit") Integer Limit);

　　//按照条件 联合Salary表查询
　　List<Map<String, Object>> queryAuthorAndSalary(@Param("where1") Integer where1, @Param("where2") Integer where2);
}

二、基于myBatis实现Dao层接口的编程

1、在resourse - mapper - 创建SeckillDao.xml

2、id属性的值对应 Dao接口里面的方法

3、“<=” 号 会引发错误  需要转换  "<![CDATA[ <= ]]>"

4、#{值}是Dao接口里面方法的参数

<?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.example.seckill.Dao.SeckillDao">
    <update id="updateSeckillById">
        update
          seckill
        set
          number=number-1
        where Id=#{Id}
        and start_time <![CDATA[ <= ]]> #{killtime}
        and end_time>=#{killtime}
        and number>0;
    </update>

    <select id="qurryById" resultType="Seckill" parameterType="Integer">
          select Id,name,number,start_time,end_time,create_time
          from seckill
          where Id=#{Id};
    </select>

    <select id="qurryAll" resultType="Seckill">
          select Id,name,number,start_time,end_time,create_time
          from seckill
          order by create_time desc
          limit #{offet},#{Limit};
    </select>

    <select id="queryAuthorAndSalary" resultType="java.util.Map">
        select * from
        t_author as a INNER join t_salary s on a.o_id=s.id
        <if test="where1 ==1">
            AND a.o_id =3
        </if>
        <if test="where1 ==2">
            AND s.welfare like'五险%'
        </if>
    </select>

</mapper>

三、myBatis整合Spring编程

1、在 resourses - spring - 创建 spring-Dao.xml 文件

2、具体代码注释如下

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 整合MyBatis过程-->

    <!-- 1:配置数据库相关连接参数-->
    <context:property-placeholder location="classpath:jdbc.properties" />
    <!-- 2:数据库连接池-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!-- 配置连接池属性-->
        <property name="driverClass" value="${driver}" />
        <property name="jdbcUrl" value="${url}" />
        <property name="user" value="${user}" />
        <property name="password" value="${password}" />

        <!-- c3p0连接池私有属性-->
        <property name="maxPoolSize" value="30" />
        <property name="minPoolSize" value="10"/>
        <!-- 关闭连接后不自动conmit-->
        <property name="autoCommitOnClose" value="false"/>
        <!-- 获取连接超时时间-->
        <property name="checkoutTimeout" value="1000"/>
        <!-- 当获取连接失败重试次数-->
        <property name="acquireRetryAttempts" value="2" />
    </bean>

    <!-- 3:配置sqlSessionFactory对象-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 注入数据库连接池  上面的bean-->
        <property name="dataSource" ref="dataSource"/>
        <!-- 配置MyBatis全局配置文件mybatis-config.xml-->
        <property name="configLocation" value="classpath:mybatis-config"/>
        <!-- 扫描entity包  使用别名-->
        <property name="typeAliasesPackage" value="com.example.seckill.Entity"/>
        <!-- 扫描sql配置文件：mapper需要的xml文件-->
        <property name="mapperLocations" value="classpath:mapper/*"/>
    </bean>

    <!-- 4:配置扫描Dao接口包，动态实现Dao接口，注入到spring容器中-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 注入sqlSessionFactory-->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
        <!-- 给出需要扫描Dao接口包-->
        <property name="basePackage" value="com.example.seckill.Dao"/>
    </bean>

</beans>

四、测试及结果

1、直接调用Dao接口方法

    @Test
    public void qurryById() {
        Integer Id=3;
        Seckill seckill = seckillDao.qurryById(Id);
        System.out.println(seckill.getName());
    }

Spring boot整合MyBatis

在配置文件application.yml添加

mybatis:
  type-aliases-package: com.panshi.ProjectMyBatis.Entity
  mapper-locations: classpath:mapper/*.xml