Mybatis学习笔记：一、Mybatis开发流程

1.创建一个Maven工程

添加Maven依赖

<dependencies>
	<dependency>
		<groupId>org.mybatis</groupId>
		<artifactId>mybatis</artifactId>
		<version>3.4.6</version>
	</dependency>
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
		<version>5.1.39</version>
	</dependency>
</dependencies>

2.创建数据库和表

创建一个mybatis的数据库，以及一个t_dept部门表，建表sql如下：

CREATE TABLE `t_dept` (
  `id` int(2) NOT NULL AUTO_INCREMENT COMMENT 'id',
  `dept_name` varchar(20) DEFAULT NULL COMMENT '部门名称',
  `location` varchar(20) DEFAULT NULL COMMENT '所属地区',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

3.在工程中创建实体类

public class Dept {

	private Integer id;
	private String deptName;
	private String location;
	
	public Integer getId() {
		return id;
	}
	
	public void setId(Integer id) {
		this.id = id;
	}
	
	public String getDeptName() {
		return deptName;
	}
	
	public void setDeptName(String deptName) {
		this.deptName = deptName;
	}
	
	public String getLocation() {
		return location;
	}
	
	public void setLocation(String location) {
		this.location = location;
	}
	
	
}

4.创建sql映射文件

在src/main/resource下创建与当前表对应的SQL映射文件用于声明SQL语句

可以从官网中（ctrl+f搜“namespace”）找到相应的头文件，后面还会细说，这里先拿来引用

DeptMapper.xml

<?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="Dept">
	<insert id="insertDept">
	    insert into t_dept (id, dept_name, location) values (
	    	#{id}, #{deptName}, #{location}
	    )
	</insert>
</mapper>

5.创建Mybais核心配置文件

在src/main/resources下创建Mybatis-config.xml作为核心配置文件

在刚才给出官网中（ctrl+f搜“environments”）找到相应的头文件

<?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.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf8&autoReconnect=true"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <mapper resource="DeptMapper.xml"/>
  </mappers>
</configuration>

6.编写测试类，测试sql的执行

public class Test {

	public static void main(String[] args) throws IOException {
		Dept dept = new Dept();
		dept.setDeptName("部门1");
		dept.setLocation("北京市");
		InputStream is = Resources.getResourceAsStream("Mybatis-config.xml");
		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);
		SqlSession session = factory.openSession();
		session.insert("insertDept", dept);
		session.commit();
		session.close();
	}
}

7.运行sql语句，控制台没有报错，我们再看数据库中，已经插入成功

整个包结构及路径如下

下一节，会分析一下Mybatis的基本调用流程