Mybatis 学习笔记 --Mybatis 的概念与入门案例，java 中高级面试题最新
address varchar(256) default null comment '地址',
primary key (id)
) engine=InnoDB DEFAULT CHARSET =utf8;
新建 maven 工程：
目录结构：
在 pom.xml 中导入相关依赖 jar 包：
<?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>org.example</groupId>
<artifactId>mybatis_day01</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>8.0.11</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>
配置封装数据库数据的 User 类：
public class User implements Serializable {
private Integer id;
private String username;
private Date birthday;
private String sex;
private String address;
public Integer getId() {return id;}
public void setId(Integer id) {this.id =id;}
public String getUsername() {return username;}
public void setUsername(String username) {this.username = username;}
public Date getBirthday() {return birthday;}
public void setBirthday(Date birthday) {this.birthday = birthday;}
public String getSex() {return sex;}
public void setSex(String sex) {this.sex = sex;}
public String getAddress() {return address;}
public void setAddress(String address) {this.address = address;}
@Override
public String toS
tring() {
return "User{" +
"id=" + id +
", username='" + username + ''' +
", birthday=" + birthday +
", sex='" + sex + ''' +
", address='" + address + ''' +
'}';
}
}
配置持久层接口 IUserDao：
/**
用户持久层接口
*/
public interface IUserDao {
/**
查询所有
@return
*/
List<User> findAll();
}
配置接口映射文件 IUserDao.xml：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.IUserDao">
<select id="findAll" resultType="com.User">
select * from user
</select>
</mapper>
配置 SqlMapConfig.xml：
<?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>
<properties>
<property name="driver" value="com.mysql.cj.jdbc.Driver"></property>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf-8"></property>
<property name="username" value="root"></property>
<property name="password" value="123456"></property>
</properties>
<environments default="mysql">
<environment id="mysql">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"></property>
<property name="url" value="${url}"></property>
<property name="username" value="${username}"></property>
<property name="password" value="${password}"></property>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/IUserDao.xml"/>
</mappers>
</configuration>
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