mybatis基本使用

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mybatis-config.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>
    <properties resource="db.properties"/>
<typeAliases>
    <!--<typeAlias type="com.xxx.pojo.User" alias="User"></typeAlias>-->
    <package name="com.xxx.pojo"></package>
</typeAliases>
<environments default="test">
    <!--<environment id="development">-->
        <!--<transactionManager type="JDBC"/>-->
        <!--<dataSource type="POOLED">-->
            <!--<property name="driver" value="com.mysql.jdbc.Driver"/>-->
            <!--<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;"/>-->
            <!--<property name="username" value="root"/>-->
            <!--<property name="password" value="123456"/>-->
        <!--</dataSource>-->
    <!--</environment>-->
    <environment id="test">
        <transactionManager type="JDBC"/>
        <dataSource type="POOLED">
            <property name="driver" value="${driver}"/>
            <property name="url" value="${url}"/>
            <property name="username" value="${username}"/>
            <property name="password" value="${password}"/>
        </dataSource>
    </environment>
</environments>
<mappers>
    <mapper resource="com/xxx/dao/UserMapper.xml"/>
</mappers>
</configuration>

MybatisUtils.java

package com.xxx.util;

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 java.io.IOException;
import java.io.InputStream;

/**
 * @author xzy
 * @create 2022/5/26 21:16
 */
public class MybatisUtils {

    static private SqlSessionFactory sqlSessionFactory;
    public MybatisUtils(){
    }

    static public SqlSession getSqlSession(){
        try {
            String resource = "mybatis-config.xml";
            //获取SqlSessionFactory对象
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sqlSessionFactory.openSession();
    }
}

User.java

package com.xxx.pojo;

import org.apache.ibatis.type.Alias;

/**
 * @author xzy
 * @create 2022/5/26 21:31
 */
@Alias("User")
public class User {
    private int iduser;
    private String username;
    private String pwd;

    public User() {
    }

    public User(int iduser, String namename, String pwd) {
        this.iduser = iduser;
        this.username = namename;
        this.pwd = pwd;
    }

    @Override
    public String toString() {
        return "User{" +
                "iduser=" + iduser +
                ", namename='" + username + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }

    public int getIduser() {
        return iduser;
    }

    public void setIduser(int iduser) {
        this.iduser = iduser;
    }

    public String getNamename() {
        return username;
    }

    public void setNamename(String namename) {
        this.username = namename;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
}

UserMapper.java

package com.xxx.dao;

import com.xxx.pojo.User;

import java.util.List;
import java.util.Map;

/**
 * @author xzy
 * @create 2022/5/26 21:37
 */
public interface UserMapper {
    List<User> getUserList();
    User getUserById(int id);
    int addUser(User user);
    int updateUser(User user);
    int deleteUser(int id);
}

UserMapper.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">
<mapper namespace="com.xxx.dao.UserMapper">

    <select id="getUserList" resultType="user">
      SELECT * FROM mybatis.user;
    </select>
    <select id="getUserById" parameterType="int" resultType="com.xxx.pojo.User">
      SELECT * FROM mybatis.user where iduser = #{id}
    </select>
    <insert id="addUser" parameterType="com.xxx.pojo.User">
      insert into mybatis.user (iduser,username,pwd) value (#{iduser},#{username},#{pwd});
    </insert>
    <update id="updateUser" parameterType="com.xxx.pojo.User">
        update mybatis.user set username=#{username},pwd=#{pwd} where iduser=#{iduser};
    </update>
    <delete id="deleteUser" parameterType="int">
        delete from mybatis.user where iduser = #{id};
    </delete>

</mapper>