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简单使用mybatis(idea中使用)讲解

leader 2021年02月13日 程序员 143 0

首先创建一个maven项目

第一步:在pom.xml中添加依赖

<dependencies> 
        <!--mybatis--> 
        <dependency> 
            <groupId>org.mybatis</groupId> 
            <artifactId>mybatis</artifactId> 
            <version>3.4.6</version> 
        </dependency> 
        <!--数据库相关 jar 包--> 
        <dependency> 
            <groupId>org.mariadb.jdbc</groupId> 
            <artifactId>mariadb-java-client</artifactId> 
            <version>2.3.0</version> 
        </dependency> 
        <!-- JUnit单元测试工具 --> 
    <dependency> 
        <groupId>junit</groupId> 
        <artifactId>junit</artifactId> 
        <version>4.10</version> 
    </dependency> 
    </dependencies>

第二步:创建数据库表

CREATE TABLE BOOK( 
ID INT AUTO_INCREMENT PRIMARY KEY, 
NAME VARCHAR(20), 
NUMBER int ); 
insert into BOOK(NAME,NUMBER) VALUES 
('Java程序设计',10), 
('数据结构',10), 
('设计模式',10)

第三步:在main目录下的java源代码写代码

实体类Book

package com.wbg.entity; 
 
public class Book { 
    int id; 
    String name; 
    int number; 
 
    @Override 
    public String toString() { 
        return "Book{" + 
                "id=" + id + 
                ", name='" + name + '\'' + 
                ", number=" + number + 
                '}'; 
    } 
 
    public int getId() { 
        return id; 
    } 
 
    public void setId(int id) { 
        this.id = id; 
    } 
 
    public Book() { 
    } 
 
    public String getName() { 
        return name; 
    } 
 
    public void setName(String name) { 
        this.name = name; 
    } 
 
    public int getNumber() { 
        return number; 
    } 
 
    public void setNumber(int number) { 
        this.number = number; 
    } 
 
    public Book(int id, String name, int number) { 
        this.id = id; 
        this.name = name; 
        this.number = number; 
    } 
}
View Code

bookMapper接口

package com.wbg.dao; 
 
import com.wbg.entity.Book; 
 
public interface bookMapper { 
    Book selectBookById(); 
}

BookDao

package com.wbg.dao; 
 
import com.wbg.entity.Book; 
import org.apache.ibatis.session.SqlSession; 
import org.apache.ibatis.session.SqlSessionFactory; 
import org.apache.ibatis.session.SqlSessionFactoryBuilder; 
 
import java.io.InputStream; 
 
public class BookDao { 
    public Book getBookById(int id){ 
        //使用类加载器加载mybatis的配置文件 
        InputStream inputStream=BookDao.class.getClassLoader().getResourceAsStream("config.xml"); 
        //构建sqlSession的工厂 
        SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream); 
        //创建能执行映射文件中的sql 
        SqlSession sqlSession=sqlSessionFactory.openSession(); 
 
        Book book=sqlSession.selectOne("com.wbg.dao.bookMapper.selectBookById",2); 
          return book; 
    } 
 
    public static void main(String[] args) { 
        BookDao bookDao=new BookDao(); 
        System.out.println(bookDao.getBookById(1)); 
    } 
}
View Code

第四步:在resources中创建config.xml配置资源文件

<?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> 
    <environments default="development"> 
        <environment id="development"> 
            <transactionManager type="JDBC"/> 
            <dataSource type="POOLED"> 
                <property name="driver" value="org.mariadb.jdbc.Driver"/> 
                <property name="url" value="jdbc:mariadb://localhost:3306/stu"/> 
                <property name="username" value="root"/> 
                <property name="password" value="123456"/> 
            </dataSource> 
        </environment> 
    </environments> 
    <mappers> 
        <mapper resource="mapper/bookMapper.xml"/> 
    </mappers> 
</configuration>

第五步:在resources中创建mapper目录,在目录下创建bookMapper.xml配置文件

<?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"> 
<mapper namespace="com.wbg.dao.bookMapper"> 
    <select id="selectBookById" resultType="com.wbg.entity.Book"> 
        select * from Book where id=#{id} 
    </select> 
</mapper>

测试

 

 项目下载地址:https://github.com/weibanggang/mybatistest

 

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