目的:使用mybatis用id查詢數據
第一步:導入相對應的jar包
第二步:配置dtd約束(只有配置了約束才可以進行xml自動提示)
https://blog.csdn.net/a15920804969/article/details/79107852
第三步:準備好一張表,和相對應的pojo(domain)
3-1、user表
3-2、pojo
- package com.ziyang.mybatis.pojo;
- import java.io.Serializable;
- import java.util.Date;
- public class User implements Serializable {
- /**
- *
- */
- private static final long serialVersionUID = 1L;
- private Integer id;
- private String username;
- private String sex;
- private Date birthday;
- private String address;
- 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 getSex() {
- return sex;
- }
- public void setSex(String 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 "User [id=" + id + ", username=" + username + ", sex=" + sex
- + ", birthday=" + birthday + ", address=" + address + "]";
- }
- }
第四步:sqlmap的創建(也就是寫sql語句的地方)
- /li>
- PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
- "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
- select * from user where id = #{a}
第五步:配置mybatis主配置文件 (sqlMapConfig.xml)
- /li>
- PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
- "http://mybatis.org/dtd/mybatis-3-config.dtd">
- value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8" />
第六步:測試:
- package com.ziyang.mybatis.test;
- import java.io.IOException;
- import java.io.InputStream;
- 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.Test;
- import com.ziyang.mybatis.pojo.User;
- public class Demo_1 {
- @Test
- public void test1() throws IOException {
- //加載核心配置文件
- InputStream stream = Resources.getResourceAsStream("sqlMapConfig.xml");
- //創建一個sqlSessionFactory
- SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(stream);
- //創建sqlsession
- SqlSession sqlSession = sqlSessionFactory.openSession();
- //執行sql語句
- User user = sqlSession.selectOne("test.findUserById",1);
- System.out.println(user);
- }
- }
結構目錄:
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