MyBatis的CRUD
- 2019 年 10 月 7 日
- 筆記
MyBatis的增删改查，特点是只要定义接口，不用实现方法，sql语句在xml中配置，非常方便
文件结构
接口UserDao
import com.jinke.domain.QueryVo;import com.jinke.domain.User; import java.util.List; public interface UserDao { List<User> findAll(); void saveUser(User user); void updateUser(User user); void deleteUser(Integer userId); User findById(Integer userId); List<User> findByName(String username); int findTotal(); List<User> findUserByVo(QueryVo vo);}
实体类User
import java.io.Serializable;import java.util.Date; public class User implements Serializable { private Integer id; private String username; private String address; private String sex; private Date birthday; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } @Override public String toString() { return "User{" + "id=" + id + ", username='" + username + ''' + ", address='" + address + ''' + ", sex='" + sex + ''' + ", birthday=" + birthday + '}'; }}
实体封装
public class QueryVo { private User user; public User getUser() { return user; } public void setUser(User user) { this.user = user; }}
SqlMapConfig.xml
<?xml version="1.0" encoding="utf-8" ?><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 2.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration> <!--配置环境--> <environments default="mysql"> <!--配置mysql的环境--> <environment id="mysql"> <!--配置事务--> <transactionManager type="JDBC"></transactionManager> <!--配置连接池--> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf8"/> <property name="username" value="root"/> <property name="password" value="1234"/> </dataSource> </environment> </environments> <!--配置映射文件的位置--> <mappers> <mapper resource="com/jinke/dao/UserDao.xml"/> </mappers></configuration>
sql语句
<?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.jinke.dao.UserDao"> <!--解决实体属性和表字段不一致的问题--> <resultMap id="userMap" type="com.jinke.domain.User"> <id property="id" column="id"/> <result property="username" column="username"/> <result property="address" column="address"/> <result property="sex" column="sex"/> <result property="birthday" column="birthday"/> </resultMap> <select id="findAll" resultMap="userMap"> select * from user; </select> <!-- <select id="findAll" resultType="com.jinke.domain.User"> select * from user; </select>--> <insert id="saveUser" parameterType="com.jinke.domain.User"> /*配置插入操作后，获取插入数据的id*/ <selectKey keyProperty="id" keyColumn="id" resultType="int" order="AFTER"> select last_insert_id(); </selectKey> insert into user(username,address,sex,birthday) values(#{username},#{address},#{sex},#{birthday}); </insert> <update id="updateUser" parameterType="com.jinke.domain.User"> update user set username = #{username},address = #{address},sex = #{sex},birthday = #{birthday} where id = #{id}; </update> <delete id="deleteUser" parameterType="Integer"> delete from user where id = #{uid}; </delete> <select id="findById" parameterType="Integer" resultType="com.jinke.domain.User"> select * from user where id = #{uid}; </select> <select id="findByName" parameterType="String" resultType="com.jinke.domain.User"> select * from user where username like #{name} /*select * from user where username like '%${value}%'*/ </select> <select id="findTotal" resultType="Integer"> select count(id) from user; </select> <!--查询类型封装--> <select id="findUserByVo" parameterType="com.jinke.domain.QueryVo" resultType="com.jinke.domain.User"> select * from user where username like #{user.username} </select></mapper>
测试类
import com.jinke.dao.UserDao;import com.jinke.domain.QueryVo;import com.jinke.domain.User;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.InputStream;import java.util.Date;import java.util.List; public class MyBatisTest { private InputStream in; private SqlSession sqlSession; private UserDao userDao; @Before public void init() throws Exception { in = Resources.getResourceAsStream("SqlMapConfig.xml"); SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder(); SqlSessionFactory factory = builder.build(in); sqlSession = factory.openSession(); userDao = sqlSession.getMapper(UserDao.class); } @After public void destroy() throws Exception { sqlSession.commit(); sqlSession.close(); in.close(); } @Test public void testFindAll() { List<User> users = userDao.findAll(); for (User user : users) { System.out.println(user); } } @Test public void testSave() { User user = new User(); user.setUsername("李四"); user.setAddress("上海"); user.setBirthday(new Date()); user.setSex("男"); userDao.saveUser(user); } @Test public void testUpdate() { User user = new User(); user.setId(2); user.setUsername("王五"); user.setAddress("广州"); user.setBirthday(new Date()); user.setSex("男"); userDao.updateUser(user); } @Test public void testDelete() { userDao.deleteUser(2); } @Test public void testFindOne() { User user = userDao.findById(1); System.out.println(user); } @Test public void testFindByName() { List<User> users = userDao.findByName("%张%"); for (User user : users) { System.out.println(user); } } @Test public void testFindTotal() { int total = userDao.findTotal(); System.out.println("total" + total); } @Test public void testFindByVo() { QueryVo vo = new QueryVo(); User user = new User(); user.setUsername("%张%"); vo.setUser(user); List<User> users = userDao.findUserByVo(vo); for (User u : users) { System.out.println(u); } }}
