MyBatis入门（四）---动态SQL
2025-02-02 06:04:14 来源: 阅读:
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 '21' 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); } }