公共的SqlMapConfig.xml
这两个例子里面，都有用到//src//SqlMapConfig.xml文件
这是个公共文件，内容如下
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMapConfig PUBLIC "-//ibatis.apache.org//DTD SQL Map Config 2.0//EN" "http://ibatis.apache.org/dtd/sql-map-config-2.dtd">
<sqlMapConfig>
<settings useStatementNamespaces="true"/>
<transactionManager type="JDBC">
<dataSource type="SIMPLE">
<property name="JDBC.Driver" value="oracle.jdbc.OracleDriver"/>
<property name="JDBC.ConnectionURL" value="jdbc:oracle:thin:@127.0.0.1:1521:jadyer"/>
<property name="JDBC.Username" value="scott"/>
<property name="JDBC.Password" value="jadyer"/>
</dataSource>
</transactionManager>
<sqlMap resource="com/jadyer/model/User.xml"/>
<sqlMap resource="com/jadyer/model/People.xml"/>
</sqlMapConfig>
一对多映射
首先是两个实体类User.java以及Address.java
package com.jadyer.model;
import java.util.List;
public class User {
private Integer id;
private String name;
private String job;
private List<Address> addresses;
/* 四个属性的setter和getter略 */
}
package com.jadyer.model;
public class Address {
private Integer id;
private Integer userId;
private String address;
private Integer postcode;
/* 四个属性的setter和getter略 */
}
接下来是实体类映射文件com/jadyer/model/User.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN" "http://ibatis.apache.org/dtd/sql-map-2.dtd">
<sqlMap namespace="User">
<typeAlias alias="user" type="com.jadyer.model.User"/>
<typeAlias alias="address" type="com.jadyer.model.Address"/>
<!-- 通过在<resultMap/>中定义嵌套查询getAddressByUserId，实现了关联数据的读取 -->
<resultMap id="get-user-result" class="user">
<result property="id" column="ID"/>
<result property="name" column="NAME"/>
<result property="job" column="JOB"/>
<result property="addresses" column="id" select="User.getAddressesByUserId"/>
</resultMap>
<select id="getAddressesByUserId" parameterClass="int" resultClass="address">
select address, postcode from t_address where user_id = #userId#
</select>
<select id="getUsers" resultMap="get-user-result">
select id, name, job from t_user
</select>
<select id="getUserByName" parameterClass="java.lang.String" resultMap="get-user-result">
select id, name, job from t_user where name = #name#
</select>
</sqlMap>
下面是用到的数据库脚本文件
-- Oracle 11g
-- Create table
create table t_user(
id number,
name varchar2(10),
job varchar2(20)
);
create table t_address(
id number,
user_id number,
address varchar2(20),
postcode number
);
-- Add data
insert into t_user values(1, '沈浪', '侠客');
insert into t_user values(2, '王怜花', '军师');
insert into t_user values(3, '金不换', '财务');
insert into t_address values(1, 1, '来无影去无踪', 999999);
insert into t_address values(2, 1, '赏金侠客天君', 888888);
insert into t_address values(3, 1, '万剑山庄之主', 777777);
insert into t_address values(4, 2, '鬼魅狐影奸狭', 666666);
insert into t_address values(5, 2, '易容之术无敌', 555555);
insert into t_address values(6, 3, '鬼迷心窍恋财', 444444);
insert into t_address values(7, 3, '厚颜无耻杯具', 333333);
最后是JUnit4.x的单元测试类IBatisOneToManyTest.java
package com.jadyer.test;
import java.io.IOException;
import java.io.Reader;
import java.sql.SQLException;
import java.util.List;
import org.junit.BeforeClass;
import org.junit.Test;
import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;
import com.jadyer.model.Address;
import com.jadyer.model.User;
public class IBatisOneToManyTest {
private static SqlMapClient sqlMapClient;
/**
* 读取ibatis配置文件，连接数据库，并创建SqlMapClient
*/
@BeforeClass
public static void readConfig() throws IOException {
Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");
sqlMapClient = SqlMapClientBuilder.buildSqlMapClient(reader);
reader.close();
}
/**
* 获取所有用户的，包含了地址的，详细资料
*/
@Test
public void getUsers() throws SQLException {
List<User> userList = sqlMapClient.queryForList("User.getUsers");
for(User user : userList){
System.out.println("==>" + user.getName() + "：" + user.getJob());
for(Address address : user.getAddresses()){
System.out.println(address.getAddress() + "---" +address.getPostcode());
}
}
}
/**
* 获取指定用户的，包含了地址的，详细资料
*/
@Test
public void getUserByName() throws SQLException {
User user = (User)sqlMapClient.queryForObject("User.getUserByName", "王怜花");
System.out.println("==>" + user.getName() + "：" + user.getJob());
for(Address address : user.getAddresses()){
System.out.println(address.getAddress() + "---" +address.getPostcode());
}
}
}
一对一映射
首先是实体类People.java
package com.jadyer.model;
public class People {
private Integer id;
private String name;
private String job;
private String sex;
private String card;
/* 四个属性的setter和getter略 */
}
接下来是实体类映射文件com/jadyer/model/People.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN" "http://ibatis.apache.org/dtd/sql-map-2.dtd">
<sqlMap namespace="People">
<typeAlias alias="people" type="com.jadyer.model.People"/>
<resultMap id="get-people-result" class="people">
<result property="id" column="ID"/>
<result property="name" column="NAME"/>
<result property="job" column="JOB"/>
<result property="sex" column="SEX"/>
<result property="card" column="CARD"/>
</resultMap>
<!--
一对一关联是一对多关联的一种特例
这种情况下，若用一对多的编写方式，将导致1+1条SQL的执行
所以，我们可以采用一次Select两张表的方式，避免这样的性能开销
这个时候，应该保证People类中包含sex和card两个属性，并且一个People类就够了，不需要Identity类
-->
<select id="getPeoples" resultMap="get-people-result">
select * from t_people, t_identity where t_people.id = t_identity.people_id
</select>
<select id="getPeopleByName" parameterClass="java.lang.String" resultMap="get-people-result">
select * from t_people, t_identity where name = #name# and t_people.id = t_identity.people_id
</select>
</sqlMap>
下面是数据库脚本文件
-- Oracle 11g
-- Create table
create table t_people(
id number,
name varchar2(8),
job varchar2(20)
);
create table t_identity(
id number,
people_id number,
sex varchar2(2),
card number
);
-- Add data
insert into t_people values(1, '张起灵', '武器');
insert into t_people values(2, '陈文锦', '领队');
insert into t_people values(3, '吴三省', '插班');
insert into t_identity values(1, 1, '男', 777777777777);
insert into t_identity values(2, 2, '女', 666666666666);
insert into t_identity values(3, 3, '男', 555555555555);
最后是JUnit4.x的单元测试类IBatisOneToOneTest.java
package com.jadyer.test;
import java.io.IOException;
import java.io.Reader;
import java.sql.SQLException;
import java.util.List;
import org.junit.BeforeClass;
import org.junit.Test;
import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;
import com.jadyer.model.People;
public class IbatisOneToOneTest {
private static SqlMapClient sqlMapClient;
/**
* 读取ibatis配置文件，连接数据库，并创建SqlMapClient
*/
@BeforeClass
public static void readConfig() throws IOException {
Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");
sqlMapClient = SqlMapClientBuilder.buildSqlMapClient(reader);
reader.close();
}
/**
* 获取所有用户的，包含了身份证的，详细资料
*/
@Test
public void getPeoples() throws SQLException {
List<People> peopleList = sqlMapClient.queryForList("People.getPeoples");
for(People people : peopleList){
System.out.println("==>" + people.getName() + "：" + people.getCard());
}
}
/**
* 获取指定用户的，包含了身份证的，详细资料
*/
@Test
public void getPeopleByName() throws SQLException {
People people = (People)sqlMapClient.queryForObject("People.getPeopleByName", "陈文锦");
System.out.println("==>" + people.getName() + "：" + people.getCard());
}
}