mybatis（1）：入坑篇
依赖
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.0</version>
</dependency>
<!-- 测试数据库 -->
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>2.3.4</version>
</dependency>
myBatis 配置
<?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>
<!-- 引入properties配置文件 -->
<properties resource="jdbc.properties"/>
<environments default="test">
<environment id="test">
<transactionManager type="JDBC" />
<dataSource type="UNPOOLED">
<property name="driver" value="${hsqldb.driver}" />
<property name="url" value="${hsqldb.url}" />
<property name="username" value="${hsqldb.username}" />
<property name="password" value="${hsqldb.password}" />
</dataSource>
</environment>
</environments>
<mappers>
<!-- mapping 配置： 加载 Mapper.xml 和 Mapper.class -->
<mapper class="com.github.xsj.model.Mapper"/>
</mappers>
</configuration>
映射配置
使用 Mapper wrapper
package com.github.xsj.model;
public class User {
private Long id; // id 使用 Long 类型而非 long
private String name;
...
}
Wrapper：
package com.github.xsj.model;
public interface Mapper {
User getUser(long id);
void insertUser(User user);
@Update("update users set name = #{name}")
void updateUser(User user);
@Delete("delete from users where id = #{id}")
void deleteUser(long id);
}
映射文件: src\main\resources\com\github\xsj\model\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.github.xsj.model.Mapper">
<select id="getUser" resultType="com.github.xsj.model.User">
select * from users where id = #{id}
</select>
<!-- get generated key! Note: keyColumn 之所以使用 ID 而非 id 是 hsqldb 将列名强行转换为大写所导致 -->
<insert id="insertUser" useGeneratedKeys="true" keyProperty="id" keyColumn="ID">
insert into users values(#{id}, #{name})
</insert>
</mapper>
单元测试
sql 脚本
drop table users if exists;
create table users (
id INTEGER GENERATED BY DEFAULT AS IDENTITY(START WITH 1, INCREMENT BY 1) primary key,
name varchar(126) not null
);
insert into users(name) values('User1');
样例
public class BaseTest {
private final static Logger log = LoggerFactory.getLogger(BaseTest.class);
private static SqlSessionFactory sqlSessionFactory;
@BeforeClass
public static void setUp() throws Exception{
Reader reader = Resources.getResourceAsReader("mybatis-test-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
reader.close();
// 数据初始化
SqlSession session = sqlSessionFactory.openSession();
Connection conn = session.getConnection();
reader = Resources.getResourceAsReader("com/github/xsj/model/CreateDB.sql");
ScriptRunner runner = new ScriptRunner(conn);
runner.setLogWriter(new PrintWriter(System.out));
runner.runScript(reader);
reader.close();
conn.close();
session.close();
}
@Test
public void selectTest() {
SqlSession session = sqlSessionFactory.openSession();
try {
Mapper mapper = session.getMapper(Mapper.class);
assertThat(mapper.getUser(1), is(notNullValue()));
} finally {
session.close();
}
}
...
}
