Jar包导入,生成数据库表,创建与src同级资源目录config,test目录(注意,config,test均为资源目录)
在这里非接口开发和hibernate玩起来一模一样,也是先创建实体类DBUser,再建实体类对应的映射文件DBUser.xml(局部xml文件),再将DBUser.xml mapper到SqlMapConfig.xml(全局配置文件),再弄个测试类Demo1来测下
实体类:DBUser.java
package com.xiangshuai.mybatis;
import java.util.Date;
public classDBUser {
private int id;
private Integer sex;
private Date birthday;
private String address;
private String username;
public DBUser(Integer sex, Date birthday, String address, String username) {
super();
this.sex = sex;
this.birthday = birthday;
this.address = address;
this.username = username;
}
public DBUser() {
super();
// TODO Auto-generated constructor stub
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public Integer getSex() {
return sex;
}
public void setSex(Integer sex) {
this.sex = sex;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "DBUser [id="+ id + ", sex="+ sex+ ", birthday=" + birthday+ ", address=" + address+ ", username="
+username + "]";
}
}
建实体类对应的映射文件DBUser.xml(局部xml文件)
<?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">
<!-- namespace:命名空间,对statement的信息进行分类管理 -->
<!-- 注意:在mapper代理时,它具有特殊及重要的作用 -->
<mapper namespace="test">
<!-- 根据用户ID查询用户信息 -->
<!-- select:表示一个MappedStatement对象 -->
<!-- id:statement的唯一标示 -->
<!-- #{}:表示一个占位符? -->
<!-- #{id}:里面的id表示输入参数的参数名称,如果该参数是简单类型,那么#{}里面的参数名称可以任意 -->
<!-- parameterType:输入参数的java类型 -->
<!-- resultType:输出结果的所映射的java类型(单条结果所对应的java类型) -->
<select id="findDBUserById" parameterType="int"
resultType="com.xiangshuai.mybatis.DBUser">
SELECT* FROM DBUSER WHERE id =#{id}
</select>
<update id="udateDBUser" parameterType="com.xiangshuai.mybatis.DBUser">
UPDATE DBUSER SET username=#{username},sex=#{sex},birthday=#{birthday},address=#{address}where id=#{id}
</update>
<delete id="deleteDBUser" parameterType="int">
DELETE FROM DBUSER WHERE id=#{id}
</delete>
<!-- 增加后入参的dbuser对象仍然没有带id,如果要数据库持久化后入参带id,则需要在insert标签中加seleteKey标签从数据库中将id
查出来再赋予给入参下个id="insertDBUser1"就是mysql主键是int类型自增就是这样的 -->
<insert id="insertDBUser" parameterType="com.xiangshuai.mybatis.DBUser">
INSERT INTO DBUSER
(username,birthday,sex,address)
VALUES(#{username},#{birthday},#{sex},#{address});
</insert>
<!-- 根据用户名称模糊查询用户列表 -->
<!-- ${}:表示一个sql的连接符,会原样输出,而#{}会转成varchar也就是String类型
比如一个id为int类型id=3 #{id}后会变成'3' 但${value}就是3-->
<!-- ${value}:里面的value表示输入参数的参数名称,如果该参数是简单类型,那么${}里面的参数名称必须是value -->
<!-- ${}这种写法存在sql注入的风险,所以要慎用!!但是在一些场景下,必须使用${},比如排序时,动态传入排序的列名,${}会原样输出,-->
<select id="findDBUsersByName" parameterType="java.lang.String"
resultType="com.xiangshuai.mybatis.DBUser">
SELECT* FROM DBUSER WHERE username LIKE '%${value}%'
</select>
<select id="findDBUsersByName2" parameterType="java.lang.String"
resultType="com.xiangshuai.mybatis.DBUser">
SELECT* FROM DBUSER WHERE USERNAME LIKE '%${value}%'
</select>
<!-- 添加用户 -->
<!-- selectKey:查询主键,在标签内需要输入查询主键的sql -->
<!-- order:指定查询主键的sql和insert语句的执行顺序,相当于insert语句来说
AFTER之后也就是在执行完insert完成持久化记录之后 将这条记录的id查出来再赋值给入参参数DBUse对象 -->
<!-- LAST_INSERT_ID:该函数是mysql的函数,获取自增主键的ID,它必须配合insert语句一起使用 -->
<insert id="insertDBUser1" parameterType="com.xiangshuai.mybatis.DBUser">
<selectKey keyProperty="id" resultType="int"order="AFTER">
SELECTLAST_INSERT_ID()
</selectKey>
INSERTINTO DBUSER
(username,birthday,sex,address)
VALUES(#{username},#{birthday},#{sex},#{address})
</insert>
<!-- 自增主键之UUID -->
<insert id="insertDBUser2" parameterType="com.xiangshuai.mybatis.DBUser">
<selectKey keyProperty="id" resultType="string"order="BEFORE">
SELECTUUID()
</selectKey>
INSERTINTO DBUSER
(id,username,birthday,sex,address)
VALUES(#{id},#{username},#{birthday},#{sex},#{address})
</insert>
<!-- 自增主键之UUID oralce序列自增-->
<insert id="insertDBUser3" parameterType="com.xiangshuai.mybatis.DBUser">
<selectKey keyProperty="id" resultType="int"order="BEFORE">
SELECTseq.nextval FROM dual
</selectKey>
INSERTINTO DBUSER
(id,username,birthday,sex,address)
VALUES(#{id},#{username},#{birthday},#{sex},#{address})
</insert>
</mapper>
SqlMapConfig.xml(全局配置文件)
<?xml version="1.0"encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 加载java的配置文件或者声明属性信息 -->
<properties resource="db.properties">
</properties>
<!-- <settings></settings> -->
<!-- 自定义别名 -->
<!-- <typeAliases>
单个别名定义
<typeAliastype="com.itheima.mybatis.po.User" alias="user"/>
批量别名定义(推荐)
package:指定包名称来为该包下的po类声明别名,默认的别名就是类名(首字母大小写都可)
<packagename="com.itheima.mybatis.po" />
</typeAliases>
-->
<!-- 配置mybatis的环境信息,与spring整合,该信息由spring来管理 -->
<environments default="development">
<environment id="development">
<!-- 配置JDBC事务控制,由mybatis进行管理 -->
<transactionManager type="JDBC"></transactionManager>
<!-- 配置数据源,采用mybatis连接池 -->
<dataSource type="POOLED">
<property name="driver" value="${db.driver}"/>
<property name="url" value="${db.url}"/>
<property name="username" value="${db.username}"/>
<property name="password" value="${db.password}"/>
</dataSource>
</environment>
</environments>
<!-- 加载映射文件 -->
<mappers>
<mapper resource="DBUser.xml" />
<!-- <mapper resource="mapper/UserMapper.xml"/> -->
<!-- 批量加载映射文件 -->
<!-- <packagename="com.itheima.mybatis.mapper" /> -->
</mappers>
</configuration>
测试类Demo1
package com.xiangshuai.test;
import java.io.IOException;
import java.io.InputStream;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;
import com.xiangshuai.mybatis.DBUser;
public classDemo1 {
/*mybatis开发方式1:查询,操作和hibernate很像,也是先造实体类,然后配实体类的XML映射文件,然后将实体类的XML映射文件mapper到全局映射 XML文件
SqlMapConfig.xml中去,
* */
private SqlSessionFactory sqlSessionFactory;
private SqlSession sqlSession;
//before在每个执行@Test之前都会执行的方法
@Before
public void before(){
//读取配置文件
//全局配置文件的路径
Stringresource = "SqlMapConfig.xml";
InputStreaminputStream = null;
try {
inputStream = Resources.getResourceAsStream(resource);
}catch(IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//创建SqlSessionFactory
sqlSessionFactory = newSqlSessionFactoryBuilder().build(inputStream);
//创建SqlSession
sqlSession = sqlSessionFactory.openSession();
}
@Test
public void findDBUserById(){
//调用SqlSession的增删改查方法
//第一个参数:表示statement的唯一标示,namespace.id(DBUser.xml中sql标签 id)
DBUseruser = sqlSession.selectOne("test.findDBUserById",1);
System.out.println(user);
//关闭资源
sqlSession.close();
}
//模糊查询之 like '%${value}%',之所以不用 %#{username}%是因为 mybatis 将#{username}转成 %'诗'%而不是像${}原样输出
@Test
public void findDBUserByUsername(){
//调用SqlSession的增删改查方法
//第一个参数:表示statement的唯一标示,namespace.id(DBUser.xml中sql标签 id)
List<DBUser> users = sqlSession.selectList("test.findDBUsersByName2", "诗");
System.out.println(users);
//关闭资源
sqlSession.close();
}
@Test
public void updateDBUser(){
//调用SqlSession的增删改查方法
//第一个参数:表示statement的唯一标示,namespace.id(DBUser.xml中sql标签 id)
DBUseruser = sqlSession.selectOne("test.findDBUserById",1);
user.setUsername("王小二");user.setSex(2);user.setBirthday(new Date());user.setAddress("广东广州");
sqlSession.insert("test.udateDBUser",user);
sqlSession.commit();
//关闭资源
sqlSession.close();
}
@Test
public void deleteDBUserById(){
sqlSession.delete("test.deleteDBUser",32);
sqlSession.commit();
//关闭资源
sqlSession.close();
}
//在insert标签中不加selectKey标签,不返回id给dbuser对象的增加测试
@Test
public void insertUser() throws ParseException{
SimpleDateFormatsdf = new SimpleDateFormat("yyyy-MM-dd");
Dateda = sdf.parse("1997-11-12");
DBUseruser = new DBUser(1,da,"广西梧州","刘小诗");
sqlSession.insert("test.insertDBUser",user);
sqlSession.commit();
sqlSession.close();
System.out.println(user);//打印结果无id,但数据库中已经有这条id记录 DBUser [id=0,sex=1, birthday=Wed Nov 12 00:00:00 CST 1997, address=广西梧州, username=刘小诗]
}
//在insert标签中加selectKey标签,并且设order="AFTER"表示在insert持久化后将这条记录的id查出粜,赋给入参 dbuser对象的增加测试
@Test
public void insertUserHaveId() throws ParseException{
SimpleDateFormatsdf = new SimpleDateFormat("yyyy-MM-dd");
Dateda = sdf.parse("1997-11-13");
DBUseruser = new DBUser(1,da,"北京西城","刘诗诗");
sqlSession.insert("test.insertDBUser1",user);
sqlSession.commit();
sqlSession.close();
System.out.println(user);//打印结果带id的DBUser [id=36, sex=1,birthday=Thu Nov 13 00:00:00 CST 1997, address=北京西城, username=刘诗诗]
}
}