在IDEA中用Mybatis插入数据

在IDEA中用Mybatis插入数据

1.首先，我们在Maven中引入相关的Mybatis的jar包：

<dependencies>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.19</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

我这里用的是mysql8.0的，用5.7的小伙伴们导入对应的版本就行
2.导入的jar后我们就需要写一个用来制造SqlSession对象的工厂：

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;

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

    }
}

在这里我们用到了mybatis的核心配置文件
3.编写mybatis的核心配置文件：

<?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="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/school?characterEncoding=utf8&amp;useSSL=false&amp;serverTimezone=UTC&amp;rewriteBatchedStatements=true"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/pxy/dao/GradeMapper.xml"/>
    </mappers>
</configuration>

最下面的mapper是用来映射对应的需要执行的接口
4.我们对数据库中的Graed表进行实体类的封装：

public class Grade {
    private int gradeId;
    private String gradeName;

    public int getGradeId() {
        return gradeId;
    }

    public void setGradeId(int gradeId) {
        this.gradeId = gradeId;
    }

    public String getGradeName() {
        return gradeName;
    }

    public void setGradeName(String gradeName) {
        this.gradeName = gradeName;
    }

    public Grade() {
    }

    @Override
    public String toString() {
        return "Grade{" +
                "gradeId=" + gradeId +
                ", gradeName='" + gradeName + '\'' +
                '}';
    }

    public Grade(int gradeId, String gradeName) {
        this.gradeId = gradeId;
        this.gradeName = gradeName;
    }
}

5.在dao中写需要插入的接口方法：

import com.pxy.pojo.Grade;

import java.util.List;

public interface GradeMapper {
    List<Grade> getGradeList();


    int addGrade(Grade grade);
}

6.编写接口的xml配置;

<?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.pxy.dao.GradeMapper">
    <select id="getGradeList" resultType="com.pxy.pojo.Grade">
    select * from school.grade;
  </select>
    <insert id="addGrade" parameterType="com.pxy.pojo.Grade">
        insert into school.grade(gradeid,gradename) values (#{gradeId},#{gradeName});
    </insert>
</mapper>

这里的namespace会对我们上一步写到的接口进行一个映射
下面的id对应的就是接口中的方法名
result是接口的返回值
parameterType是参数类型
最后在<></>中写sql就好了
7.最后编写一个Test类测试一下：

 @Test
    public void addGrade(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        GradeMapper mapper = sqlSession.getMapper(GradeMapper.class);
        mapper.addGrade(new Grade(55,"研一百"));
        sqlSession.commit();
        System.out.println("插入成功！");
        sqlSession.close();
    }

插入成功！

这是我第一次写博客，大佬们有什么不对的地方欢迎指出来，谢谢！

本文地址：https://blog.csdn.net/weixin_46005468/article/details/107351987