Mybatis 快速入门(注解方式)

导读

　　注解开发的方式只需要程序员开发Mapper接口即可，不需要编写映射文件（XML）。

环境搭建

项目结构

SqlMapConfig.xml

<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!-- 引入外部配置文件 -->
    <properties resource="db.properties"></properties>
    <!-- 数据库链接相关 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${db.driver}" />
                <property name="url" value="${db.url}" />
                <property name="username" value="${db.username}" />
                <property name="password" value="${db.password}" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!-- 添加单个接口 -->
        <!-- <mapper class="com.cyb.anno.AnnotationDeptMapper" /> -->
        <!-- 批量添加 -->
       <package name="com.cyb.anno"/>
    </mappers>
</configuration>

db.properties

db.driver=com.mysql.jdbc.Driver
db.url=jdbc:mysql://127.0.0.1:3306/cyb
db.username=root
db.password=root

Dept.java

package com.cyb.po;

public class Dept {
    private int id;
    private String name;
    private int sex;
    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 int getSex() {
        return sex;
    }
    public void setSex(int sex) {
        this.sex = sex;
    }
    @Override
    public String toString() {
        return "Dept [id=" + id + ", name=" + name + ", sex=" + sex + "]";
    }
}

AnnotationDeptMapper.java(接口)

package com.cyb.anno;

import java.util.List;
import org.apache.ibatis.annotations.Select;

import com.cyb.po.Dept;

public interface AnnotationDeptMapper {
    @Select("SELECT * FROM dept WHERE id = #{id}")
    public Dept findDeptById(int id);

    @Select("SELECT * FROM dept where name like '%${value}%'")
    public List<Dept> findDeptList(String name);
}

TestDept.java

package com.cyb.test;

import java.io.InputStream;
import java.util.List;
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 org.junit.Before;
import org.junit.Test;
import com.cyb.anno.AnnotationDeptMapper;
import com.cyb.po.Dept;

public class TestDept {
    private SqlSessionFactory sqlSessionFactory;

    @Before
    public void init() throws Exception {
        //指定全局配置文件路径
        String resource = "SqlMapConfig.xml";
        //加载资源文件(包括全局文件和映射文件)
        InputStream inputStream = Resources.getResourceAsStream(resource);
        //使用构建者模式创建SqlSessionFactory
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }

    @Test
    public void testSelect() {
        //由SqlSessionFactory工厂去创建SqlSession(会话)
        SqlSession sqlSession = sqlSessionFactory.openSession();
        AnnotationDeptMapper deptMapper = sqlSession.getMapper(AnnotationDeptMapper.class);
        List<Dept> dept=deptMapper.findDeptList("al");
        System.out.println(dept.size());
        //释放资源
        sqlSession.close();
    }
}

数据库表结果及数据

测试

注解方式

查询

测试

插入

测试

插入时主键返回

测试

更新

测试

删除

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