一.MyBatis持久层框架
MyBatis的前身就是iBatis,iBatis本是apache的一个开源项目,2010年5月这个项目由apahce sofeware foundation 迁移到了google code,并且改名为MyBatis。
MyBatis 是支持普通 SQL 查询,存储过程和高级映射的优秀持久层框架。MyBatis 消除了几乎所有的 JDBC 代码和参数的手工设置以及结果集的检索。
简化JDBC的开发
能够更好的完成ORM(对象关系映射)
1.内部组件结构图
2.准备数据表
create database mybatisdb default character set utf8;
use mybatisdb;
create table user(id int primary key auto_increment,name varchar(100),addr varchar(100),age int);
Insert into user values(null,'hanmeimei','北京',28);
Insert into user values(null,'xiongda','上海',20);
Insert into user values(null,'xiaonger','上海',19);
DROP TABLE IF EXISTS `dept`;
CREATE TABLE `dept` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`dname` varchar(14) DEFAULT NULL,
`loc` varchar(13) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of dept
-- ----------------------------
INSERT INTO `dept` VALUES ('1', '呵呵呵', '一区');
INSERT INTO `dept` VALUES ('2', '哈哈哈哈', '二区');
INSERT INTO `dept` VALUES ('3', 'operations', '二区');
INSERT INTO `dept` VALUES ('5', 'java教研部', '大钟寺');
INSERT INTO `dept` VALUES ('10', '开发', '西二旗');
DROP TABLE IF EXISTS `emp`;
CREATE TABLE `emp` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`ename` varchar(10) DEFAULT NULL,
`job` varchar(9) DEFAULT NULL,
`mgr` decimal(4,0) DEFAULT NULL,
`hiredate` date DEFAULT NULL,
`sal` decimal(7,2) DEFAULT NULL,
`comm` decimal(7,2) DEFAULT NULL,
`deptno` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=510 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of emp
-- ----------------------------
INSERT INTO `emp` VALUES ('100', 'jack', '副总', null, '2002-05-03', '90000.00', null, '1');
INSERT INTO `emp` VALUES ('200', 'tony', '总监', '100', '2015-02-02', '10000.00', '2000.00', '2');
INSERT INTO `emp` VALUES ('300', 'hana', '经理', '200', '2017-02-02', '8000.00', '1000.00', '2');
INSERT INTO `emp` VALUES ('400', 'leo', '员工', '300', '2019-02-22', '3000.00', '200.12', '2');
INSERT INTO `emp` VALUES ('500', 'liu', '员工', '300', '2019-03-19', '3500.00', '200.58', '2');
INSERT INTO `emp` VALUES ('502', '王一博', 'topidol.', '1000', '2021-03-31', '20000.00', '99.00', '88');
INSERT INTO `emp` VALUES ('504', '蔡徐坤', 'rapper', '10', '2021-03-29', '100.00', '1000.00', '100');
二.MyBatis:XML映射方式
1.Maven工程结构
注:导入jUnit5,使用@BeforeEach注解替代jUnit4的@Before。
2. pom.xml
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>cn.tedu</groupId>
<artifactId>mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>mybatis</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.2</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!--mybatis依赖包-->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.4</version>
</dependency>
<!--jdbc依赖包-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.48</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</depe