MyBatis入门（四）---动态SQL

一、创建数据库表

1.1、创建表

USE `mybatis`;

/*Table structure for table `user` */

DROP TABLE IF EXISTS `user`;

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户ID',
  `name` varchar(45) NOT NULL DEFAULT '无名氏' COMMENT '用户名',
  `age` tinyint(3) NOT NULL DEFAULT '' COMMENT '用户年龄',
  `birthday` datetime NOT NULL DEFAULT '1970-01-01 00:00:00' COMMENT '用户生日',
  `address` varchar(256) NOT NULL DEFAULT '北京' COMMENT '用户地址',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=18 DEFAULT CHARSET=utf8 COMMENT='用户表';

/*Data for the table `user` */

insert  into `user`(`id`,`name`,`age`,`birthday`,`address`)
values (1,'赵敏',23,'1990-01-23 20:24:21','明教'),
(2,'李四',18,'1986-12-23 12:13:11','广州'),
(3,'张五',33,'1975-09-23 02:13:11','上海'),
(4,'王六',27,'1984-11-01 11:23:14','重庆'),
(5,'张三丰',108,'1971-01-02 02:12:11','武当'),
(6,'想起 来叫什么了',22,'1984-01-23 20:23:22','魔都上海'),
(7,'呵呵',22,'1984-01-23 20:23:22','不知道是哪的'),
(8,'张无忌',18,'2015-10-28 15:31:31','明教');

二、创建项目导入Jar包

2.1、

三、创建实现类和Mybatis各个配置文件 

3.1、创建pojo类

/**
*/
package com.pb.mybatis.po;

import java.util.Date;

/**  

 * @Title: User.java

 * @Package com.pb.mybatis.po

 * @ClassName User

 * @Description: TODO(用户类)

 * @author 刘楠 

 * @date 2015-10-30 下午4:27:05

 * @version V1.0  

 */
public class User {

    //用户ID
    private int id;
    //用户名
    private String name;
    //用户年龄
    private int age;
    //生日
    private Date birthday;
    //地址
    private String address;
    /**
     * @return the id
     */
    public int getId() {
        return id;
    }
    /**
     * @param id the id to set
     */
    public void setId(int id) {
        this.id = id;
    }
    /**
     * @return the name
     */
    public String getName() {
        return name;
    }
    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }
    /**
     * @return the age
     */
    public int getAge() {
        return age;
    }
    /**
     * @param age the age to set
     */
    public void setAge(int age) {
        this.age = age;
    }
    /**
     * @return the birthday
     */
    public Date getBirthday() {
        return birthday;
    }
    /**
     * @param birthday the birthday to set
     */
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    /**
     * @return the address
     */
    public String getAddress() {
        return address;
    }
    /**
     * @param address the address to set
     */
    public void setAddress(String address) {
        this.address = address;
    }
    /** (non Javadoc)

     * <p>Title: toString</p>

     * <p>Description: </p>

     * @return

     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", age=" + age
                + ", birthday=" + birthday + ", address=" + address + "]";
    }

}

3.2、创建db.properties

#数据库基本配置信息
#驱动
jdbc.driver=com.mysql.jdbc.Driver
#连接URL
jdbc.url=jdbc:mysql://localhost:3306/mybatis?CharacterEncoding=utf8
#用户名
jdbc.username=root
#密码
jdbc.password=root

log4j

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# MyBatis logging configuration...
# 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

3.3、创建UserMapper与mapper.xml

/**
*/
package com.pb.mybatis.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Param;

import com.pb.mybatis.po.User;

/**  

 * @Title: UserMapper.java

 * @Package com.pb.mybatis.mapper

 * @ClassName UserMapper

 * @Description: TODO(用户类数据访问层Mapper接口)

 * @author 刘楠 

 * @date 2015-10-30 下午6:17:43

 * @version V1.0  

 */
public interface UserMapper {

    public User findUserById(int id);

    /**
     *
     * @Title: findUserByWhere

     * @Description: TODO(根据条件查询用户)

     * @return List<User>
     */
    public List<User> findUserByWhere(@Param("id") int id,@Param("name")String username);

    /**
     *
     * @Title: updateUser

     * @Description: TODO(修改)

     * @param user
     * @return int
     */
    public int updateUser(User user);

}

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.pb.mybatis.mapper.UserMapper">
<!-- 映射 -->

<resultMap type="User" id="userResultMap">
<id property="id" column="id"/>
<result property="name" column="name"/>
<result property="age" column="age"/>
<result property="birthday" column="birthday"/>
<result property="address" column="address"/>
</resultMap>

<select id="findUserById" parameterType="int" resultMap="userResultMap">
select * from user where id=#{id}
</select>

<!-- 根据条件查询用户 -->
<select id="findUserByWhere" resultMap="userResultMap">
select * from user
<where>
<!--where会自动去掉第一个成功的条件的and和or  -->
<if test="id!=null and id!='' and id!=0">
and id=#{id}
</if>
<if test="name!=null and name!=''">
or name like "%"#{name}"%"
</if>
</where>
</select>

<!--修改
SET NAME=#{name},
age=#{age},
birthday=#{birthday},
address=#{address}
-->
<update id="updateUser" parameterType="User">
UPDATE USER
<!--使用SET来更新  -->
<set>
<if test="name !=null and name !=''">NAME=#{name},</if>
<if test="age !=null  and age !='' and age !=0">age=#{age},</if>
<if test="birthday !=null">birthday=#{birthday},</if>
<if test="address !=null and address !=''">address=#{address}</if>
</set>
WHERE id=#{id}
</update>

</mapper>

3.4、创建configuration.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">

<configuration>
<properties resource="db.properties" />
<typeAliases>
<!--使用默认别名  -->
<package name="com.pb.mybatis.po"/>
</typeAliases>
<environments default="development">
<environment id="development">
    <transactionManager type="JDBC"/>
    <dataSource type="POOLED">
        <property name="driver" value="${jdbc.driver}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </dataSource>
</environment>
</environments>
<mappers>
<!-- 加载映射 -->
<package name="com.pb.mybatis.mapper"/>
</mappers>
</configuration>

3.5、测试

/**
*/
package com.pb.mybatis.mapper;

import static org.junit.Assert.*;

import java.io.InputStream;
import java.util.Date;
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.junit.Before;
import org.junit.Test;

import com.pb.mybatis.po.User;

/**  

 * @Title: UserMapperTest.java

 * @Package com.pb.mybatis.mapper

 * @ClassName UserMapperTest

 * @Description: TODO(用一句话描述该文件做什么)

 * @author 刘楠 

 * @date 2015-10-30 下午6:25:23

 * @version V1.0  

 */
public class UserMapperTest {

private SqlSessionFactory sqlSessionFactory;

    /**
     *
     * @Title: setUp

     * @Description: TODO(在每个方法前执行的方法)

     * @throws Exception void
     */
    @Before
    public void setUp() throws Exception {
        String resource="configuration.xml";
        InputStream in=Resources.getResourceAsStream(resource);
        //获取会话工厂
        sqlSessionFactory=new SqlSessionFactoryBuilder().build(in);
    }

    @Test
    public void testFindUserById() {
        //获取会话
        SqlSession sqlSession=sqlSessionFactory.openSession();
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);
        User user=userMapper.findUserById(1);
        System.out.println(user);
    }

    @Test
    public void testFindUserByWhere() {
        //获取会话
        SqlSession sqlSession=sqlSessionFactory.openSession();
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);
        List<User> list=userMapper.findUserByWhere(0,"");
        System.out.println(list);
    }

    @Test
    public void testUpdateUser() {
        //获取会话
        SqlSession sqlSession=sqlSessionFactory.openSession();
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);
        User user=userMapper.findUserById(6);
        System.out.println(user);
        user.setBirthday(new Date());

        user.setName("sssss");
        user.setAddress("ddd");
        int num=userMapper.updateUser(user);
        sqlSession.commit();
        System.out.println("num="+num);

    }
}