mybatis整理笔记

以下是idea2018辑编器

新建 Maven工程

1  file ->new ->project

新建后编程器在右下角加载插件。，这个时候需要会儿，  加载好后，软件目录会多一个ja包

类似于：

为了测试数据库，需要建一个表，

然后新建查询方式：

CREATE TABLE `user` (
`id` int(11) NOT NULL auto_increment,
`username` varchar(32) NOT NULL COMMENT '用户名称',
`birthday` datetime default NULL COMMENT '生日',
`sex` char(1) default NULL COMMENT '性别',
`address` varchar(256) default NULL COMMENT '地址',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

新建一个表，，在通过命令添加数据：

nsert into `user`(`id`,`username`,`birthday`,`sex`,`address`) values (41,'老王','2018-02-27 17:47:08','男','北京'),(42,'小二王','2018-03-02 15:09:37','女','北京金燕龙'),(43,'小二王','2018-03-04 11:34:34','女','北京金燕龙'),(45,'传智播客','2018-03-04 12:04:06','男','北京金燕龙'),(46,'老王','2018-03-07 17:37:26','男','北京'),(48,'小马宝莉','2018-03-08 11:44:00','女','北京修正');

然后通主包配置加载所需插件：

在pom.xml 中添加：　　

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.itheima</groupId>
    <artifactId>day01_eesy_01mybatis</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
        </dependency>

    </dependencies>

</project>

其中解释如下：

如此以后会自动安装上面所涉及到的包有工具库  以上前期工作完成

第二步

开始新建模型  orm  所谓模型就是给对象一样的字段  在src -main-java  中新建一个包  com.itheima-domain

在里面建一个类user

详细模型代码如下：

 1 package com.itheima.domain;
 2
 3 import java.io.Serializable;
 4 import java.util.Date;
 5
 6 public class User  implements Serializable {
 7     private Integer id;
 8     private String username;
 9     private Date birthday;
10     private String sex;
11     private String address;
12
13     public Integer getId() {
14         return id;
15     }
16
17     public void setId(Integer id) {
18         this.id = id;
19     }
20
21     public String getUsername() {
22         return username;
23     }
24
25     public void setUsername(String username) {
26         this.username = username;
27     }
28
29     public Date getBirthday() {
30         return birthday;
31     }
32
33     public void setBirthday(Date birthday) {
34         this.birthday = birthday;
35     }
36
37     public String getSex() {
38         return sex;
39     }
40
41     public void setSex(String sex) {
42         this.sex = sex;
43     }
44
45     public String getAddress() {
46         return address;
47     }
48
49     public void setAddress(String address) {
50         this.address = address;
51     }
52
53     @Override
54     public String toString() {
55         return "User{" +
56                 "id=" + id +
57                 ", username='" + username + '\'' +
58                 ", birthday=" + birthday +
59                 ", sex='" + sex + '\'' +
60                 ", address='" + address + '\'' +
61                 '}';
62     }
63 }

然后配置主配置，关于数据库和资源的

主配置文件内容如下：

<?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>
    <!--主配置-->
    <environments default="mysql">
        <environment id="mysql">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver"  value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/eesy"/>
                <property name="username" value="root"/>
                <property name="password" value="142857"/>
            </dataSource>
        </environment>
    </environments>
    <!--yanse-->
    <mappers>
        <mapper resource="com/itheima/dao/IUserDao.xml"/>
    </mappers>

</configuration>

然后一个查询配置，代码如下：src-main-java 新建包  com.itheima.dao   IUserDao.xml

package com.itheima.dao;
import com.itheima.domain.User;
import java.util.List;

public interface IUserDao {
    List<User> findAll();

}

开始测试

resources类下新建测试  com.itheima.dao.text

MybaisTest

package com.itheima.test;

import com.itheima.dao.IUserDao;
import com.itheima.domain.User;
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.InputStream;
import java.util.List;

public class MybatisTest {

    public static void main(String[] args)throws Exception {
        //1.读取配置文件
        InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.创建SqlSessionFactory工厂
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        SqlSessionFactory factory = builder.build(in);
        //3.使用工厂生产SqlSession对象
        SqlSession session = factory.openSession();
        //4.使用SqlSession创建Dao接口的代理对象
        IUserDao userDao = session.getMapper(IUserDao.class);
        //5.使用代理对象执行方法
        List<User> users = userDao.findAll();
        for(User user : users){
            System.out.println(user);
        }
        //6.释放资源
        session.close();
        in.close();
    }
}

完成第一个dome