mybatis进阶

1.mybatis一对一映射

Student--Card

<?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.juaner.one2one.Student">
    <resultMap id="studentMap" type="com.juaner.one2one.Student">
        <id property="id" column="sid"/>
        <result property="name" column="sname"/>
        <!--引入CardMapper.xml文件中的映射
            property:Student类的关联属性
            resultMap:引入CardMapper.xml中的映射类型 namespace+id
            -->
        <association property="card" resultMap="com.juaner.one2one.Card.cardMap"/>
    </resultMap>
    <select id="findById" parameterType="int" resultMap="studentMap">
        SELECT s.sid,s.sname,c.cid,c.cnum
        FROM student s,card c
        WHERE s.scid = c.cid
        AND c.cid =#{id}
    </select>
    <!--只封装查询出来的字段-->
    <select id="findByName" parameterType="string" resultMap="studentMap">
        SELECT s.sid,c.cnum
        FROM student s,card c
        WHERE s.scid = c.cid
        AND s.sname = #{name}
    </select>
</mapper>

<?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.juaner.one2one.Card">
    <resultMap id="cardMap" type="com.juaner.one2one.Card">
        <id property="id" column="cid"/>
        <result property="num" column="cnum"/>
    </resultMap>
</mapper>

2.mybatis一对多映射

Student---Grade

<?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.juaner.one2many.Student">
    <resultMap id="studentMap" type="com.juaner.one2many.Student">
        <id property="id" column="sid"/>
        <result property="name" column="sname"/>
        <association property="grade" resultMap="com.juaner.one2many.Grade.gradeMap"/>
    </resultMap>
    <select id="findAllByName" parameterType="string" resultMap="studentMap">
        SELECT s.sid,s.sname,g.gid,g.gname
        FROM studentg s,grade g
        WHERE s.sgid = g.gid
        AND g.gname=#{name}
    </select>
</mapper>

<mapper namespace="com.juaner.one2many.Grade">
    <resultMap id="gradeMap" type="com.juaner.one2many.Grade">
        <id property="id" column="gid"/>
        <result property="name" column="gname"/>
    </resultMap>
    <select id="findByName" parameterType="string" resultMap="gradeMap">
        SELECT s.sid,s.sname,g.gid,g.gname
        FROM studentg s,grade g
        WHERE s.sgid = g.gid
        AND s.sname = #{name}
    </select>
</mapper>

3.mybatis多对多映射

Student--Course

<?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.juaner.many2many.Student">
    <resultMap id="studentMap" type="com.juaner.many2many.Student">
        <id property="id" column="sid"/>
        <result property="name" column="sname"/>
    </resultMap>
    <select id="findAllByCourseName" parameterType="string" resultMap="studentMap">
        SELECT s.sid,s.sname,c.cid,c.cname
        FROM studentc s,courses c,middles m
        WHERE s.sid = m.msid AND c.cid=m.mcid
        AND c.cname=#{name}
    </select>
</mapper>

<?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.juaner.many2many.Course">
    <resultMap id="courseMap" type="com.juaner.many2many.Course">
        <id property="id" column="cid"/>
        <result property="name" column="cname"/>
    </resultMap>
    <select id="findAllByName" parameterType="string" resultMap="courseMap">
        SELECT s.sid,s.sname,c.cid,c.cname
        FROM studentc s,courses c,middles m
        WHERE s.sid = m.msid AND c.cid=m.mcid
        AND s.sname = #{name}
    </select>
</mapper>

4.spring + mybatis + oracle开发

1）创建一个spring-mybaits-oracle javaweb工程

2)导入spring，mybatis，c3p0，oracle和mybatis提供的与spring整合的插件包

mysql的jar：
mysql-connector-java-5.1.7-bin.jar
oracle的jar：
ojdbc5.jar
c3p0的jar：
c3p0-0.9.1.2.jar
mybatis的jar：
asm-3.3.1.jar
cglib-2.2.2.jar
commons-logging-1.1.1.jar
mybatis-3.1.1.jar
mybatis与spring整合的jar
【mybatis-spring-1.1.1.jar】
spring的ioc模块的jar：
org.springframework.asm-3.0.5.RELEASE.jar
org.springframework.beans-3.0.5.RELEASE.jar
org.springframework.context-3.0.5.RELEASE.jar
org.springframework.core-3.0.5.RELEASE.jar
org.springframework.expression-3.0.5.RELEASE.jar
commons-logging.jar
spring的aop模块的jar：
aopalliance.jar
aspectjweaver.jar
cglib-2.2.2.jar
org.springframework.aop-3.0.5.RELEASE.jar
spring的transaction模块的jar：
org.springframework.jdbc-3.0.5.RELEASE.jar
org.springframework.orm-3.0.5.RELEASE.jar
org.springframework.transaction-3.0.5.RELEASE.jar

3)  创建emps数据库表

4）创建Emp.java类

5）创建EmpMapper.xml映射文件

6）创建mybatis.xml配置文件

<?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>
    <mappers>
        <mapper resource="com/juaner/entity/EmpMapper.xml"/>
    </mappers>
</configuration>

7）创建spring.xml配置文件

<?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"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xmlns:mvc="http://www.springframework.org/schema/mvc"
        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

          http://www.springframework.org/schema/aop
          http://www.springframework.org/schema/aop/spring-aop.xsd

          http://www.springframework.org/schema/tx
          http://www.springframework.org/schema/tx/spring-tx.xsd

          http://www.springframework.org/schema/mvc
          http://www.springframework.org/schema/mvc/spring-mvc.xsd
          ">
    <!--配置c3p0连接池-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="oracle.jdbc.driver.OracleDriver"/>
        <property name="jdbcUrl" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/>
        <property name="user" value="scott"/>
        <property name="password" value="tiger"/>
    </bean>
    <!--加载mybatis配置文件和映射文件，即替代原来的mybatis工具类作用-->
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="configLocation" value="classpath:mybatis.xml"/>
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--配置mybatis事务管理器，因为mybatis底层用的是jdbc事务管理器
        所以在这里配置jdbc事务管理器-->
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!--配置事务通知，即哪些方法需要事务支持-->
    <tx:advice id="tx" transaction-manager="txManager">
        <tx:attributes>
            <tx:method name="add*" propagation="REQUIRED"/>
            <tx:method name="update*" propagation="REQUIRED"/>
            <tx:method name="delete*" propagation="REQUIRED"/>
            <tx:method name="*" propagation="SUPPORTS"/>
        </tx:attributes>
    </tx:advice>

    <!--配置事务切面，即哪些包下的类需要事务支持-->
    <aop:config>
        <!--返回值不限 dao包下的所有类的所有方法，参数不限-->
        <aop:pointcut id="pt" expression="execution(* com.juaner.dao.*.*(..))"/>
        <!--将事务切面和事务通知结合在一起-->
        <aop:advisor advice-ref="tx" pointcut-ref="pt"/>
    </aop:config>

    <!--注册empdao-->
    <bean id="empDao" class="com.juaner.dao.EmpDao">
        <property name="sqlSessionFactory" ref="sqlSessionFactoryBean"/>
    </bean>
</beans>

8）创建EmpDao.java类

public class EmpDao {
    //自动注入
    private SqlSessionFactory sqlSessionFactory;

    public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
        this.sqlSessionFactory = sqlSessionFactory;
    }

    public void add(Emp emp)throws Exception{
        SqlSession sqlSession = sqlSessionFactory.openSession();
        sqlSession.insert(Emp.class.getName()+".add",emp);
//        int i = 1/0;
        sqlSession.close();
    }
}

9）测试

public class TestEmpDao {
    @Test
    public void test()throws Exception{
        EmpDao empDao = new EmpDao();
        empDao.add(new Emp(1,"m",6000d,"小明"));

    }
    //测试spring整合mybatis
    @Test
    public void test2()throws Exception{
        ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext(new String[]{"spring.xml"});
        EmpDao empDao = (EmpDao) ac.getBean("empDao");
        empDao.add(new Emp(2,"f",7000d,"小红"));
    }
}