mybatis链接数据库mysql8.0根据用户ID查询用户信息练习

软件：IDEA

环境：mybatis3.2.7

mysql8.0

config目录：

log4j.propertis

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

sqlMapConfig.xml

<?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>
    <!-- 和spring整合后 environments配置将废除 -->
    <environments default="development">
        <environment id="development">
            <!-- 使用jdbc事务管理 -->
            <transactionManager type="JDBC" />
            <!-- 数据库连接池 -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver" />
                <property name="url"
                          value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&amp;characterEncoding=utf-8&amp;serverTimezone=UTC&amp;useSSL=false" />
                <property name="username" value="root" />
                <property name="password" value="123456" />
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="mybatis/user.xml"/>
    </mappers>
</configuration>

mybatis包

user.xml

<?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">
<!--命名空间,用于隔离SQL语句-->
<!--#{} 点位符，相当于jdbc
    ${}  字符串拼接指令，如果入参为普通数据类型{}内为value
-->
<mapper namespace="user">
    <select id="getUserById" parameterType="int" resultType="com.mybatis.pojo.User">
        SELECT * FROM user WHERE id=#{id1}
    </select>
<!--resultType:如果返回值为集合，只需设置为每一个的数据类型-->
    <select id="getUserByUserName" parameterType="string" resultType="com.mybatis.pojo.User">
        SELECT * FROM user
         WHERE username like #{name}
         /*WHERE username like '%${value}%'*/
    </select>

</mapper>

src目录

com.mybatis.pojo

Order.java

package com.mybatis.pojo;

import java.util.Date;

public class Order {
	private Integer id;

	private Integer userId;

	private String number;

	private Date createtime;

	private String note;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public Integer getUserId() {
		return userId;
	}

	public void setUserId(Integer userId) {
		this.userId = userId;
	}

	public String getNumber() {
		return number;
	}

	public void setNumber(String number) {
		this.number = number == null ? null : number.trim();
	}

	public Date getCreatetime() {
		return createtime;
	}

	public void setCreatetime(Date createtime) {
		this.createtime = createtime;
	}

	public String getNote() {
		return note;
	}

	public void setNote(String note) {
		this.note = note == null ? null : note.trim();
	}

	@Override
	public String toString() {
		return "Order [id=" + id + ", userId=" + userId + ", number=" + number + ", createtime=" + createtime
				+ ", note=" + note + "]";
	}

}

User.java

package com.mybatis.pojo;

import java.util.Date;

public class User {

	private Integer id;
	private String username;// 用户姓名
	private String sex;// 性别
	private Date birthday;// 生日
	private String address;// 地址

	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 + "]";
	}

}

SqlSessionFactoryUtils

package com.mybatis.utils;

import com.sun.jndi.ldap.ext.StartTlsResponseImpl;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
/*sqlSessionFactory工具类*/
public class SqlSessionFactoryUtils {
  private static SqlSessionFactory sqlSessionFactory;
/*获取sqlSessionFactory*/
  public static SqlSessionFactory getSqlSessionFactory() {
    return sqlSessionFactory;
  }

  static {

    try {
      SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
      InputStream inputStream = Resources.getResourceAsStream("sqlMapConfig.xml");
      sqlSessionFactory = ssfb.build(inputStream);

    } catch (IOException e) {
      e.printStackTrace();
    }

  }
}

test

package test;

import com.mybatis.pojo.User;
import com.mybatis.utils.SqlSessionFactoryUtils;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.scripting.xmltags.ForEachSqlNode;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.InputStream;
import java.util.List;


public class MybatisTest {

    @Test
    public  void  test1() throws Exception {
        SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
        InputStream inputStream = Resources.getResourceAsStream("sqlMapConfig.xml");
        SqlSessionFactory sqlSessionFactory = ssfb.build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        User user = sqlSession.selectOne("user.getUserById", 1);
        System.out.println(user);
        sqlSession.close();
    }

    @Test
    public void testgetUserByUserName(){
        //获取sqlSessionFactory
        SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();
        //创建SqlSession
        SqlSession sqlSession = sqlSessionFactory.openSession();
       // List<User> list = sqlSession.selectList("user.getUserByUserName", "%张%");
        List<User> users = sqlSession.selectList("user.getUserByUserName", "%张%");

        for (User user: users) {
            System.out.println(user);
        }
    }
}