这一篇在上一篇的基础上简单讲解如何进行增删改查操作。
一、在mybatis的配置文件conf.xml中注册xml与注解映射
<!-- 注册映射文件 -->
<mappers>
<!-- 通过xml方式映射 -->
<mapper resource="com/mybatis/crud/userMapper.xml" />
<!-- 通过注解方式映射 -->
<mapper class="com.mybatis.crud.IUserMapper" />
</mappers>
二、在这个com.mybatis.crud包下面新建userMapper.xml文件与IUserMapper接口
1、userMapper.xml明细如下
<?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.mybatis.crud.userMapper"> <insert id="addUser" parameterType="com.mybatis.crud.User"> insert into users(id_id,name_n,age_a) values(#{id},#{name},#{age}) </insert> <delete id="deleteUser" parameterType="int"> delete from users where id_id=#{id} </delete> <update id="updateUser" parameterType="com.mybatis.crud.User"> update users set name_n=#{name},age_a=#{age} where id_id =#{id} </update> <select id="getAllUsers" resultType="com.mybatis.crud.User" resultMap="usermap"> select * from Users </select> <resultMap type="com.mybatis.crud.User" id="usermap"> <id property="id" column="id_id" /> <result property="name" column="name_n" /> <result property="age" column="age_a" /> </resultMap> <select id="getUser" parameterType="int" resultType="com.mybatis.crud.User" resultMap="usermap"> select * from Users where id_id=#{id} </select> </mapper>
2、IUserMapper接口定义如下
package com.mybatis.crud; import java.util.List; import java.util.Properties; import org.apache.ibatis.annotations.Delete; import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Result; import org.apache.ibatis.annotations.Results; import org.apache.ibatis.annotations.Select; import org.apache.ibatis.annotations.Update; import org.apache.ibatis.type.JdbcType; public interface IUserMapper { @Insert("insert into users(id_id,name_n,age_a) values(#{id},#{name},#{age})") public int add(User user); @Delete("delete from users where id_id=#{id}") public int deleteById(int id); @Update("update users set name_n=#{name},age_a=#{age} where id_id =#{id}") public int update(User user); @Select("select * from Users where id_id=#{id}") @Results({ @Result(property = "id", column = "id_id", jdbcType = JdbcType.INTEGER), @Result(property = "name", column = "name_n", jdbcType = JdbcType.VARCHAR), @Result(property= "age", column = "age_a", jdbcType = JdbcType.INTEGER) }) public User getById(int id); @Select("select * from Users") @Results({ @Result(property = "id", column = "id_id", jdbcType = JdbcType.INTEGER), @Result(property = "name", column = "name_n", jdbcType = JdbcType.VARCHAR), @Result(property= "age", column = "age_a", jdbcType = JdbcType.INTEGER) }) public List<User> getAll(); }
三、新建一个获取SqlSessionFactory的工具类
package com.mybatis.util; import java.io.InputStream; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import com.mybatis.demo.test; public class MybatisUtils { public static SqlSessionFactory getFactory(){ String resource = "conf.xml"; InputStream inputStream = test.class.getClassLoader().getResourceAsStream(resource); SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputStream); return sessionFactory; } }
四、实际测试代码如下
package com.mybatis.crud; import java.util.List; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.junit.Test; import com.mybatis.util.MybatisUtils; public class TestCrud { //方法名称上面F11键 即可运行测试方法 @Test public void testAdd() { SqlSessionFactory factory = MybatisUtils.getFactory(); SqlSession session = factory.openSession(true); String statement = "com.mybatis.crud.userMapper.addUser"; User user1 = new User(); user1.setId(199); user1.setName("wrrrugggcj"); user1.setAge(296); System.out.println("[xml]新增影响行数："+session.insert(statement, user1)); User user2 = new User(); user2.setId(198); user2.setName("wrrrugggcjeee"); user2.setAge(26); IUserMapper userMapper = session.getMapper(IUserMapper.class); System.out.println("[注解]新增影响行数："+userMapper.add( user2)); session.close(); } @Test public void testUpdate() { SqlSessionFactory factory = MybatisUtils.getFactory(); //默认手动提交 SqlSession session = factory.openSession(); String statement = "com.mybatis.crud.userMapper.updateUser"; User user1 = new User(); user1.setId(199); user1.setName("199"); user1.setAge(89); System.out.println("[xml]修改影响行数："+session.update(statement, user1)); User user2 = new User(); user2.setId(198); user2.setName("198"); user2.setAge(89); IUserMapper userMapper = session.getMapper(IUserMapper.class); System.out.println("[注解]修改影响行数："+userMapper.update(user2)); //提交 session.commit(); session.close(); } @Test public void testDelete() { SqlSessionFactory factory = MybatisUtils.getFactory(); SqlSession session = factory.openSession(true); String statement = "com.mybatis.crud.userMapper.deleteUser"; System.out.println("[xml]删除影响行数："+session.delete(statement,199)); IUserMapper userMapper = session.getMapper(IUserMapper.class); System.out.println("[注解]删除影响行数："+userMapper.deleteById(198)); session.close(); } @Test public void testGetAllusers() { SqlSessionFactory factory = MybatisUtils.getFactory(); SqlSession session = factory.openSession(true); String statement = "com.mybatis.crud.userMapper.getAllUsers"; List<User> users = session.selectList(statement); System.out.println("[xml]查询用户列表："+users); IUserMapper userMapper = session.getMapper(IUserMapper.class); System.out.println("[注解]查询用户列表："+userMapper.getAll()); session.close(); } }
至此，一个基于mybatis的简单增删改就完成了，不过建议在阅读这篇文章的时候先将入门篇看一遍就可以了。