Mybatis的CRUD（增删改查）
1.pom.xml
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.41</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.6</version>
</dependency></dependencies>
2.SqlMapperConfig.xml
<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPEconfiguration PUBLIC"-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"><!--mybatis的主配置文件--><configuration> <!--配置环境--> <environments default="mysql"> <!--配置mysql环境--> <environment id="mysql"> <!--配置事务的类型--> <transactionManager type="JDBC"></transactionManager> <!--配置数据源（连接池）--> <dataSource type="POOLED"> <!--配置连接数据库的4个基本信息--> <property name="driver" value="com.mysql.jdbc.Driver"></property> <property name="url" value="jdbc:mysql://localhost:3306/zml?useUnicode=true&characterEncoding=utf-8"></property> <property name="username" value="root"></property> <property name="password" value="root"></property> </dataSource> </environment> </environments> <!--指定映射配置文件的位置，映射配置文件指的是每个dao独立的配置文件--><mappers> <mapper resource="dao/UserDao.xml"></mapper></mappers></configuration>
3.Users.java
package entity;public class Users { private int id; private String username; private String password; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } @Override public String toString() { return "Users{" + "id=" + id + ", username='" + username + '\'' + ", password='" + password + '\'' + '}'; }}
4.UserVo.java
package entity;public class UserVo { private Users users; public Users getUsers() { return users; } public void setUsers(Users users) { this.users = users; }}
5.UserDao.java
package dao; import entity.UserVo; import entity.Users; import java.util.List;public interface UserDao { List<Users> findAll(); Users find(int id); void save(Users users); void update(Users users); void delete(int id); List<Users> findVague(String name); int count(); List<Users> findVo(UserVo vo);}
6.UserDao.xml
<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPEmapper PUBLIC"-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="dao.UserDao"> <!--查询所有--> <select id="findAll" resultType="entity.Users"> select * from users </select> <!--根据ID查询--> <select id="find" resultType="entity.Users"> select * from users where id=#{id} </select> <!--增加--> <insert id="save" parameterType="entity.Users"> <!--查询新增用户的ID--> <selectKey keyProperty="id" keyColumn="id" resultType="int" order="AFTER"> select last_insert_id() </selectKey> insert into users(username,password) values(#{username},#{password}) </insert> <!--根据ID进行修改--> <update id="update" parameterType="entity.Users"> update users set username=#{username},password=#{password} where id=#{id} </update> <!--根据ID进行删除--> <delete id="delete" parameterType="entity.Users"> delete from users where id=#{id} </delete> <!--模糊查询--> <select id="findVague" resultType="entity.Users">-- select * from users where username like '%${value}%' select * from users where username like #{name} </select> <!--查询用户总数--> <select id="count" resultType="int"> select count(id) from users </select> <!--将实体类封装到另一个实体类中的模糊查询--> <select id="findVo" resultType="entity.Users"> select * from users where username like #{users.username} </select></mapper>
7.UserTest.java
package test;import dao.UserDao;import entity.UserVo;import entity.Users;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.After;import org.junit.Before;import org.junit.Test;import java.io.IOException;import java.io.InputStream;import java.util.List;public class UserTest { private InputStream in; private SqlSession sqlSession; private UserDao UserDaoImpl; @Before public void init() throws IOException { //1.读取配置文件 in= Resources.getResourceAsStream("SqlMapperConfig.xml"); //2.创建SqlSessionFactory工厂 SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder(); SqlSessionFactory factory=builder.build(in); //3.使用工厂生产SqlSession对象 sqlSession=factory.openSession(); //4.使用SqlSession创建dao接口的代理对象 UserDaoImpl=sqlSession.getMapper(UserDao.class); } @After public void destroy() throws IOException { //提交事务 sqlSession.commit(); //6.释放资源 sqlSession.close(); in.close(); } /** * 查询所有 * @throws IOException */ @Test public void findall() throws IOException { //5.使用代理对象执行方法 List<Users> users=UserDaoImpl.findAll(); for(Users u:users){ System.out.println(u); } } /** * 增加 */ @Test public void save(){ Users users=new Users(); users.setUsername("哈哈哈"); users.setPassword("456"); UserDaoImpl.save(users); } /** * 根据ID查询并修改 */ @Test public void update(){ Users u=UserDaoImpl.find(15); u.setPassword("456"); u.setUsername("小喵"); UserDaoImpl.update(u); } /** * 根据id进行删除 */ @Test public void delete(){ UserDaoImpl.delete(16); } /** * 模糊查询，查询所有名字中有小的用户 * @throws IOException */ @Test public void findVague() throws IOException { //5.使用代理对象执行方法 List<Users> users=UserDaoImpl.findVague("%小%"); for(Users u:users){ System.out.println(u); } } /** * 查询用户总数 */ @Test public void count(){ int c=UserDaoImpl.count(); System.out.println(c); } /** * 将实体类封装到另一个实体类中的模糊查询 */ @Test public void findVo(){ UserVo vo=new UserVo(); Users users=new Users(); users.setUsername("%小%"); vo.setUsers(users); List<Users> list=UserDaoImpl.findVo(vo); for(Users u:list){ System.out.println(u); } }}
