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  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.9</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.29</version>
    </dependency>
  </dependencies>

4.將IDEA和MySQL數據庫建立連接：

根據實際情況填寫user和password 填寫之后點擊Test Connection

測試成功之后點擊Schemas選擇你要鏈接的數據庫

5.新建mybatis-config.xml配置文件引入數據庫資源

<?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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/smbms?useSSL=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/kero/dao/UserMapper.xml" />
    </mappers>
</configuration>

6.創建實體類User 注意:實體類中成員變量名要和數據庫表中字段名完全一致

package com.kero.pojo;
public class User {
    private int id;
    private String name;
    private String password;
    public User() {
    }
    public User(int id, String name, String password) {
        this.id = id;
        this.name = name;
        this.password = password;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getpassword() {
        return password;
    }
    public void setpassword(String pwd) {
        this.password = pwd;
    }
    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + password + '\'' +
                '}';
    }
}

7.編寫工具類Utils

package com.kero.utils;
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;
//sqlSessionFactory
public class MyBatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            //使用Mybatis第一步 獲取sqlSessionFactory對象
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
/*
既然有了 SqlSessionFactory，顧名思義，我們可以從中獲得 SqlSession 的實例。SqlSession
 提供了在數據庫執行 SQL 命令所需的所有方法。你可以通過 SqlSession 實例來直接執行已映射的 SQL 語句。例如：
 */
        public static SqlSession getSqlSession(){
            return sqlSessionFactory.openSession();
        }
}

8.定義接口

package com.kero.dao;
import com.kero.pojo.User;
import java.util.List;
public interface UserMapper {
  //查詢全部用戶
    List<User> getUserList();
    //根據ID查詢用戶
    User getUserByID(int id);
    //insert一個用戶
    int addUser(User user);
  //修改一個用戶
  int updateUser(User user);
  //刪除一個用戶
  int deleteUser(int id);
}

9.定義Mapper文件這里的Mapper文件相當于原來傳統方式中接口的實現類

<?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會綁定一個對應的Mapper接口-->
<mapper namespace="com.kero.dao.UserMapper">
    <select id="getUserList" resultType="com.kero.pojo.User">
        select * from smbms.user
    </select>
        <select id="getUserByID" parameterType="int" resultType="com.kero.pojo.User">
            select * from smbms.user where id = #{id}
        </select>
    <insert id="addUser" parameterType="com.kero.pojo.User">
        insert into smbms.user (id, name, password) VALUES (#{id},#{name},#{password})
    </insert>
    <update id="updateUser" parameterType="com.kero.pojo.User">
       update smbms.user set name=#{name},password=#{password} where id = #{id}
    </update>
    <delete id="deleteUser" parameterType="int">
        delete from smbms.user where id = #{id}
    </delete>
</mapper>

10.編寫測試類

import com.kero.dao.UserMapper;
import com.kero.pojo.User;
import com.kero.utils.MyBatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.List;
public class test {
    @Test
    public void test(){
        SqlSession session = MyBatisUtils.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        List<User> userList = mapper.getUserList();
        for (User l:userList) {
            System.out.println(l.toString());
        }
        session.close();
    }
    @Test
    public void testgetUserByID(){
        SqlSession session = MyBatisUtils.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        User userByID = mapper.getUserByID(1);
        System.out.println(userByID);
        session.close();
    }
    //增刪改需要提交事務
    @Test
    public void testaddUser(){
        SqlSession session = MyBatisUtils.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        int zhhgf = mapper.addUser(new User(10, "zhhgf", "1k23jbjk"));
        System.out.println(zhhgf);
        session.commit();
        //提交事務
        session.close();
    }
    @Test
    public void testupdateUser(){
        SqlSession session = MyBatisUtils.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        int i = mapper.updateUser(new User(8,"asdfsdf","234sdfs"));
        session.commit();
        //提交事務
        session.close();
    }
    @Test
    public void testdeleteUser(){
        SqlSession session = MyBatisUtils.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        int i = mapper.deleteUser(8);
        session.commit();
        //提交事務
        session.close();
    }
}

11.測試查詢功能 : 輸出結果與數據庫表中數據

User{id=1, name='Sugawara Ryota', pwd='8X8Jq7HVNs'}

User{id=2, name='Shawn Mills', pwd='R78IHGDSXr'}

User{id=3, name='Matsuda Hina', pwd='mUi3CVA7mc'}

User{id=4, name='Cynthia Hawkins', pwd='NO1EwWbOs9'}

User{id=5, name='Rachel Bennett', pwd='YefuPVxzb9'}

tips:

如果一切配置正常但出現java.lang.ExceptionInInitializerError

Caused by org.apache.ibatis.execeptions.PersistenceExecepyion錯誤

是因為:maven由于它的約定大于配置我們寫的配置文件可能會出現無法被導出或者生效的問題解決方案在pom.xml文件中添加如下代碼

<build>
  <resources>
    <resource>
      <directory>src/main/resources</directory>
      <includes>
        <include>**/*.properties</include>
        <include>**/*.xml</include>
      </includes>
      <filtering>true</filtering>
    </resource>
    <resource>
      <directory>src/main/java</directory>
      <includes>
        <include>**/*.properties</include>
        <include>**/*.xml</include>
      </includes>
      <filtering>true</filtering>
    </resource>
  </resources>
</build>

到此這篇關于Mybatis步驟分解實現一個增刪改查程序的文章就介紹到這了,更多相關Mybatis增刪改查內容請搜索html5模板網以前的文章希望大家以后多多支持html5模板網！

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Mybatis步驟分解實現一個增刪改查程序

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