07—mybatis注解配置一
常用注解
Select：映射查询的sql语句。
SelectProvider：Select语句的动态sql映射。允许指定一个类名和一个方法在执行时返回运行的查询语句。有两个属性：type和mehtod,type属性是类的完全限定名，method是该类中的那个方法名。
Insert：映射插入的sql语句。
InsertProvider：Insert语句的动态sql映射。允许指定一个类名和一个方法在执行时返回运行的插入语句。有两个属性：type和method,typet属性是类的完全限定名，method是该类中的那个方法名。
Update：映射更新的sql语句。
UpdateProvider：Update语句的动态sql映射，允许指定一个类名和一个方法在执行时返回运行的更新语句。有两个属性：type和method，type属性是类的完全限定名，method是该类中的那个方法名。
Delete：映射删除的sql语句。
DeleteProvider：Delete语句的动态sql映射。允许指定一个类名和一个方法在执行时返回运行的删除语句。有两个属性：type和method，type属性是类的完全限定名，method是该类中的那个方法名。
Results：多个结果映射（Result）列表。
Options：提供配置选项的附加值，它们通常在映射语句上作为附加功能配置出现。
One：复杂类型的单独属性值映射。必须指定Select属性，表示已对一。
一对一
1.创建表
CREATE TABLE tb_card(
id INT PRIMARY KEY AUTO_INCREMENT,
CODE VARCHAR()
);
INSERT INTO tb_card(CODE) VALUES('');
CREATE TABLE tb_person(
id INT PRIMARY KEY AUTO_INCREMENT,
NAME VARCHAR(),
sex VARCHAR(),
age INT,
card_id INT UNIQUE,
FOREIGN KEY (card_id) REFERENCES tb_card(id)
);
INSERT INTO tb_person(NAME,sex,age,card_id) VALUES('mingming','男',,)
2.创建model
Card.java
package org.fkit.domain;
import java.io.Serializable;
public class Card implements Serializable {
private Integer id; // 主键id
private String code; // 身份证编号
public Card() {
super();
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
@Override
public String toString() {
return "Card [id=" + id + ", code=" + code + "]";
}
}
Person.java
package org.fkit.domain;
import java.io.Serializable;
public class Person implements Serializable {
private Integer id; // 主键id
private String name; // 姓名
private String sex; // 性别
private Integer age; // 年龄
// 人和身份证是一对一的关系，即一个人只有一个身份证
private Card card;
public Person() {
super();
// TODO Auto-generated constructor stub
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public Card getCard() {
return card;
}
public void setCard(Card card) {
this.card = card;
}
@Override
public String toString() {
return "Person [id=" + id + ", name=" + name + ", sex=" + sex
+ ", age=" + age + "]";
}
}
3.mapper
CardMapper.java
package org.fkit.mapper;
import org.apache.ibatis.annotations.Select;
import org.fkit.domain.Card;
public interface CardMapper {
@Select("SELECT * FROM TB_CARD WHERE ID = #{id} ")
Card selectCardById(Integer id);
}
PersonMapper.java
package org.fkit.mapper;
import org.apache.ibatis.annotations.One;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.mapping.FetchType;
import org.fkit.domain.Person;
public interface PersonMapper {
@Select("SELECT * FROM TB_PERSON WHERE ID = #{id}")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="name",property="name"),
@Result(column="sex",property="sex"),
@Result(column="age",property="age"),
@Result(column="card_id",property="card",
one=@One(
select="org.fkit.mapper.CardMapper.selectCardById",
fetchType=FetchType.EAGER))
})
Person selectPersonById(Integer id);
}
4.mybatis-config.xml
db.properties
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/mybatis
username=root
password=123456
log4j.properties
# Global logging configuration
log4j.rootLogger=ERROR, stdout
# MyBatis logging configuration...
log4j.logger.org.fkit.mapper.PersonMapper=DEBUG
log4j.logger.org.fkit.mapper.CardMapper=DEBUG
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
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">
<!-- XML 配置文件包含对 MyBatis 系统的核心设置 -->
<configuration>
<properties resource="db.properties"/>
<!-- 指定 MyBatis 所用日志的具体实现 -->
<settings>
<setting name="logImpl" value="LOG4J"/>
</settings>
<environments default="mysql">
<!-- 环境配置，即连接的数据库。 -->
<environment id="mysql">
<!-- 指定事务管理类型，type="JDBC"指直接简单使用了JDBC的提交和回滚设置 -->
<transactionManager type="JDBC"/>
<!-- dataSource指数据源配置，POOLED是JDBC连接对象的数据源连接池的实现。 -->
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<!-- mappers告诉了MyBatis去哪里找持久化类的映射文件 -->
<mappers>
<mapper class="org.fkit.mapper.PersonMapper"/>
<mapper class="org.fkit.mapper.CardMapper"/>
</mappers>
</configuration>
5测试
FKSqlSessionFactory.java
package org.fkit.factory;
import java.io.InputStream;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class FKSqlSessionFactory {
private static SqlSessionFactory sqlSessionFactory = null;
// 初始化创建SqlSessionFactory对象
static{
try {
// 读取mybatis-config.xml文件
InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder()
.build(inputStream);
} catch (Exception e) {
e.printStackTrace();
}
}
// 获取SqlSession对象的静态方法
public static SqlSession getSqlSession(){
return sqlSessionFactory.openSession();
}
// 获取SqlSessionFactory的静态方法
public static SqlSessionFactory getSqlSessionFactory() {
return sqlSessionFactory;
}
}
OneToOneTest.java
package org.fkit.test;
import org.apache.ibatis.session.SqlSession;
import org.fkit.domain.Person;
import org.fkit.factory.FKSqlSessionFactory;
import org.fkit.mapper.PersonMapper;
public class OneToOneTest {
public static void main(String[] args) throws Exception {
// 获取Session实例
SqlSession session = FKSqlSessionFactory.getSqlSession();
// 获取PersonMapper实例
PersonMapper pm = session.getMapper(PersonMapper.class);
// 根据id查询Person对象，同时需要获得关联的Card对象
Person p = pm.selectPersonById(1);
// 查看查询到的Person对象
System.out.println(p);
// 查看查询到的关联的Card对象
System.out.println(p.getCard());
// 提交事务
session.commit();
// 关闭Session
session.close();
}
}
结果
DEBUG [main] - ==> Preparing: SELECT * FROM TB_PERSON WHERE ID = ?
DEBUG [main] - ==> Parameters: 1(Integer)
DEBUG [main] - ====> Preparing: SELECT * FROM TB_CARD WHERE ID = ?
DEBUG [main] - ====> Parameters: 1(Integer)
DEBUG [main] - <==== Total: 1
DEBUG [main] - <== Total: 1
Person [id=1, name=mingming, sex=男, age=28]
Card [id=1, code=150801198009191038]
一对多
1.创建表
创建表tb_clazz
CREATE TABLE tb_clazz(
id INT PRIMARY KEY AUTO_INCREMENT,
CODE VARCHAR(18),
NAME VARCHAR(18)
);
INSERT INTO tb_clazz(CODE,NAME) VALUES('2017001','Java双语幼儿园中班');
创建表tb_student
CREATE TABLE tb_student(
id INT PRIMARY KEY AUTO_INCREMENT,
NAME VARCHAR(18),
sex VARCHAR(18),
age INT,
clazz_id INT,
FOREIGN KEY (clazz_id) REFERENCES tb_clazz(id)
); INSERT INTO tb_student(NAME,sex,age,clazz_id) VALUES('aa','男',23,1);
INSERT INTO tb_student(NAME,sex,age,clazz_id) VALUES('bb','女',18,1);
INSERT INTO tb_student(NAME,sex,age,clazz_id) VALUES('cc','男',21,1);
INSERT INTO tb_student(NAME,sex,age,clazz_id) VALUES('dd','女',20,1);
2.创建model
Clazz.java
package org.fkit.domain;
import java.io.Serializable;
import java.util.List;
public class Clazz implements Serializable {
private Integer id; // 班级id，主键
private String code; // 班级编号
private String name; // 班级名称
// 班级和学生是一对多的关系，即一个班级可以有多个学生
private List<Student> students;
public Clazz() {
super();
// TODO Auto-generated constructor stub
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<Student> getStudents() {
return students;
}
public void setStudents(List<Student> students) {
this.students = students;
}
@Override
public String toString() {
return "Clazz [id=" + id + ", code=" + code + ", name=" + name + "]";
}
}
Student.java
package org.fkit.domain;
import java.io.Serializable;
public class Student implements Serializable {
private Integer id; // 学生id，主键
private String name; // 姓名
private String sex; // 性别
private Integer age; // 年龄
// 学生和班级是多对一的关系，即一个学生只属于一个班级
private Clazz clazz;
public Student() {
super();
// TODO Auto-generated constructor stub
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public Clazz getClazz() {
return clazz;
}
public void setClazz(Clazz clazz) {
this.clazz = clazz;
}
@Override
public String toString() {
return "Student [id=" + id + ", name=" + name + ", sex=" + sex
+ ", age=" + age + "]";
}
}
3.mapper
ClazzMapper.java
package org.fkit.mapper;
import org.apache.ibatis.annotations.Many;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.mapping.FetchType;
import org.fkit.domain.Clazz;
public interface ClazzMapper {
// 根据id查询班级信息
@Select("SELECT * FROM TB_CLAZZ WHERE ID = #{id}")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="code",property="code"),
@Result(column="name",property="name"),
@Result(column="id",property="students",
many=@Many(
select="org.fkit.mapper.StudentMapper.selectByClazzId",
fetchType=FetchType.LAZY))
})
Clazz selectById(Integer id);
}
StudentMapper.java
package org.fkit.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.fkit.domain.Student;
public interface StudentMapper {
// 根据班级id查询班级所有学生
@Select("SELECT * FROM TB_STUDENT WHERE CLAZZ_ID = #{id}")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="name",property="name"),
@Result(column="sex",property="sex"),
@Result(column="age",property="age")
})
List<Student> selectByClazzId(Integer clazz_id);
}
4.mybatis-config.xml
db.properties
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/mytestdb
username=root
password=root
log4j.properties
# Global logging configuration
log4j.rootLogger=ERROR, stdout
# MyBatis logging configuration...
log4j.logger.org.fkit.mapper.ClazzMapper=DEBUG
log4j.logger.org.fkit.mapper.StudentMapper=DEBUG
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
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">
<!-- XML 配置文件包含对 MyBatis 系统的核心设置 -->
<configuration>
<properties resource="db.properties"/>
<!-- 指定 MyBatis 所用日志的具体实现 -->
<settings>
<setting name="logImpl" value="LOG4J"/>
<!-- 要使延迟加载生效必须配置下面两个属性 -->
<setting name="lazyLoadingEnabled" value="true"/>
<setting name="aggressiveLazyLoading" value="false"/>
</settings>
<environments default="mysql">
<!-- 环境配置，即连接的数据库。 -->
<environment id="mysql">
<!-- 指定事务管理类型，type="JDBC"指直接简单使用了JDBC的提交和回滚设置 -->
<transactionManager type="JDBC"/>
<!-- dataSource指数据源配置，POOLED是JDBC连接对象的数据源连接池的实现。 -->
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<!-- mappers告诉了MyBatis去哪里找持久化类的映射文件 -->
<mappers>
<mapper class="org.fkit.mapper.ClazzMapper"/>
<mapper class="org.fkit.mapper.StudentMapper"/>
</mappers>
</configuration>
5.测试
FKSqlSessionFactory.java
package org.fkit.factory;
import java.io.InputStream;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class FKSqlSessionFactory {
private static SqlSessionFactory sqlSessionFactory = null;
// 初始化创建SqlSessionFactory对象
static{
try {
// 读取mybatis-config.xml文件
InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder()
.build(inputStream);
} catch (Exception e) {
e.printStackTrace();
}
}
// 获取SqlSession对象的静态方法
public static SqlSession getSqlSession(){
return sqlSessionFactory.openSession();
}
// 获取SqlSessionFactory的静态方法
public static SqlSessionFactory getSqlSessionFactory() {
return sqlSessionFactory;
}
}
结果：
DEBUG [main] - ==> Preparing: SELECT * FROM TB_CLAZZ WHERE ID = ?
DEBUG [main] - ==> Parameters: 1(Integer)
DEBUG [main] - <== Total: 1
1 2017001 Java双语幼儿园中班
DEBUG [main] - ==> Preparing: SELECT * FROM TB_STUDENT WHERE CLAZZ_ID = ?
DEBUG [main] - ==> Parameters: 1(Integer)
DEBUG [main] - <== Total: 4
Student [id=1, name=jack, sex=男, age=23]
Student [id=2, name=rose, sex=女, age=18]
Student [id=3, name=tom, sex=男, age=21]
Student [id=4, name=alice, sex=女, age=20]
多对多
1.创建表
CREATE TABLE `t_student` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`student_name` varchar(20) DEFAULT NULL,
PRIMARY KEY (`id`)
)
INSERT INTO t_student (student_name)VALUES ('小米');
INSERT INTO t_student (student_name)VALUES ('小王');
INSERT INTO t_student (student_name)VALUES ('小李'); CREATE TABLE `t_courses` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`courses_name` varchar(20) DEFAULT NULL,
PRIMARY KEY (`id`)
)
INSERT INTO t_courses (courses_name)VALUES ('java');
INSERT INTO t_courses (courses_name)VALUES ('c#');
INSERT INTO t_courses (courses_name)VALUES ('php');
INSERT INTO t_courses (courses_name)VALUES ('vb');
INSERT INTO t_courses (courses_name)VALUES ('javascript'); CREATE TABLE `t_stu_cou` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`stu_id` int(11) DEFAULT NULL,
`cou_id` int(11) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `stu_id` (`stu_id`),
KEY `cou_id` (`cou_id`),
CONSTRAINT `t_stu_cou_ibfk_1` FOREIGN KEY (`stu_id`) REFERENCES `t_student` (`id`),
CONSTRAINT `t_stu_cou_ibfk_2` FOREIGN KEY (`cou_id`) REFERENCES `t_courses` (`id`)
) INSERT INTO t_stu_cou (stu_id,cou_id)VALUES (1,1);
INSERT INTO t_stu_cou (stu_id,cou_id)VALUES (1,2);
INSERT INTO t_stu_cou (stu_id,cou_id)VALUES (1,3); INSERT INTO t_stu_cou (stu_id,cou_id)VALUES (2,2);
INSERT INTO t_stu_cou (stu_id,cou_id)VALUES (2,3);
INSERT INTO t_stu_cou (stu_id,cou_id)VALUES (2,4);
2.创建model
CoursesBean.java
package org.fkit.domain;
import java.io.Serializable;
import java.util.List;
public class CoursesBean implements Serializable{
private static final long serialVersionUID = 1L;
private Integer id;
private String name;
// 使用 List<StudentBean>集合，是说明学习这门课程的所有学生
private List<StudentBean> student;
public CoursesBean() {
super();
}
public CoursesBean(Integer id, String name, List<StudentBean> student) {
super();
this.id = id;
this.name = name;
this.student = student;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<StudentBean> getStudent() {
return student;
}
public void setStudent(List<StudentBean> student) {
this.student = student;
}
@Override
public String toString() {
return "CoursesBean [id=" + id + ", name=" + name + ", student="
+ student + "]";
}
}
StudentBean.java
package org.fkit.domain;
import java.io.Serializable;
import java.util.List;
public class StudentBean implements Serializable{
private static final long serialVersionUID = 1L;
private Integer id;
private String name;
private List<CoursesBean> courses;
public StudentBean() {
super();
}
public StudentBean(Integer id, String name, List<CoursesBean> courses) {
super();
this.id = id;
this.name = name;
this.courses = courses;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<CoursesBean> getCourses() {
return courses;
}
public void setCourses(List<CoursesBean> courses) {
this.courses = courses;
}
@Override
public String toString() {
return "StudentBean [id=" + id + ", name=" + name + ", courses="
+ courses + "]";
}
}
3.mapper
CoursesMapper.java
package org.fkit.mapper;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.mapping.FetchType;
import org.fkit.domain.CoursesBean;
import org.fkit.domain.StudentBean; import java.util.List; import org.apache.ibatis.annotations.Many; /**
* @author Administrator
*
*/
public interface CoursesMapper { /**
* 根据id查询课程
* @param id
* @return
*/
@Select("select * from t_courses where id=#{id}")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="courses_name",property="name"),
})
public CoursesBean findCouById(int id); /**
* 根据学生id查询学生的所有课程
* @param id
* @return
*/
@Select("select * from t_courses where id in (select cou_id from t_stu_cou where stu_id = #{id})")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="courses_name",property="name"),
})
public List<CoursesBean> findCoursesByStudent(int id); /**
* 要求查课时，将选课的学生一并查出
* @param id
* @return
*/
@Select("select * from t_courses where id=#{id}")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="courses_name",property="name"),
@Result(column="id",property="student",
many=@Many(select="org.fkit.mapper.StudentMapper.findStudentByCourses",fetchType=FetchType.LAZY))
})
public CoursesBean findCouAndStu(int id); }
StudentMapper.java
package org.fkit.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Many;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.mapping.FetchType;
import org.fkit.domain.CoursesBean;
import org.fkit.domain.StudentBean; public interface StudentMapper {
/**
* 根据id值查询学生信息
* @param id
* @return
*/
@Select("select * from t_student where id = #{id}")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="student_name",property="name")
})
public StudentBean findStuById(int id); /**
* 根据课程id查询课程的所有学生
* @param id
* @return
*/
@Select(" select * from t_student where id in (select stu_id from t_stu_cou where cou_id=#{id})")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="student_name",property="name")
})
public List<StudentBean> findStudentByCourses(int id);
/**
* 要求查询学生时，将学生选择的课程查出
* @param id
* @return
*/
@Select("select * from t_student where id=#{id}")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="student_name",property="name"),
@Result(column="id",property="courses",
many=@Many(select="org.fkit.mapper.CoursesMapper.findCoursesByStudent",fetchType=FetchType.LAZY))
})
public StudentBean findStuAndCou(int id); }
4.mybatis-config.xml
db.properties
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/mybatis
username=root
password=123456
log4j.properties
# Global logging configuration
log4j.rootLogger=ERROR, stdout
# MyBatis logging configuration...
log4j.logger.org.fkit.mapper.PersonMapper=DEBUG
log4j.logger.org.fkit.mapper.CardMapper=DEBUG
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
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">
<!-- XML 配置文件包含对 MyBatis 系统的核心设置 -->
<configuration>
<properties resource="db.properties" />
<!-- 指定 MyBatis 所用日志的具体实现 -->
<settings>
<setting name="logImpl" value="LOG4J" />
</settings>
<!-- 为JAVA Bean起类别名 -->
<typeAliases>
<package name="org.fkit.domain" />
</typeAliases>
<environments default="mysql">
<!-- 环境配置，即连接的数据库。 -->
<environment id="mysql">
<!-- 指定事务管理类型，type="JDBC"指直接简单使用了JDBC的提交和回滚设置 -->
<transactionManager type="JDBC" />
<!-- dataSource指数据源配置，POOLED是JDBC连接对象的数据源连接池的实现。 -->
<dataSource type="POOLED">
<property name="driver" value="${driver}" />
<property name="url" value="${url}" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
</dataSource>
</environment>
</environments>
<!-- mappers告诉了MyBatis去哪里找持久化类的映射文件 -->
<mappers>
<mapper class="org.fkit.mapper.CoursesMapper" />
<mapper class="org.fkit.mapper.StudentMapper" />
</mappers>
</configuration>
5.测试
ManyToManyTest.java
package org.fkit.test;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
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.fkit.domain.CoursesBean;
import org.fkit.domain.StudentBean;
import org.fkit.mapper.CoursesMapper;
import org.fkit.mapper.StudentMapper;
public class ManyToManyTest {
public static void main(String[] args) throws IOException {
// 读取mybatis-config.xml文件
InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
// 初始化mybatis，创建SqlSessionFactory类的实例
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder()
.build(inputStream);
// 创建Session实例
SqlSession session = sqlSessionFactory.openSession();
ManyToManyTest t = new ManyToManyTest();
// 根据用户id查询用户，测试一对多
//t.testSelectCoursesById(session);
// 根据订单id查询订单，测试多对多
t.testSelectStudentById(session); // 提交事务
session.commit();
// 关闭Session
session.close(); }
public void testSelectStudentById(SqlSession session){
// 获得UserMapper接口的代理对象
StudentMapper sm = session.getMapper(StudentMapper.class);
// 调用selectUserById方法
StudentBean stu = sm.findStuAndCou(2);
System.out.println(stu);
// 查看查询到的user对象信息
System.out.println(stu.getId() + " " + stu.getName());
// 查看user对象关联的订单信息
List<CoursesBean> CoursesList = stu.getCourses();
for(CoursesBean item : CoursesList){
System.out.println(item);
}
}
// 测试多对多，查询订单Order（多）的时候级联查询订单的商品Article（多）
public void testSelectCoursesById(SqlSession session){
// 获得OrderMapper接口的代理对象
CoursesMapper cm = session.getMapper(CoursesMapper.class);
// 调用selectOrderById方法
CoursesBean course = cm.findCouAndStu(2);
System.out.println(course);
// 查看查询到的order对象信息
System.out.println(course.getId() + " " + course.getName());
// 查看order对象关联的商品信息
List<StudentBean> studentlist = course.getStudent();
for(StudentBean stu : studentlist){
System.out.println(stu);
}
}
}
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