mybatis快速入门及错误 mybatis新手快速入门以及一些错误汇总
十维space 人气:2想了解mybatis新手快速入门以及一些错误汇总的相关内容吗，十维space在本文为您仔细讲解mybatis快速入门及错误的相关知识和一些Code实例，欢迎阅读和指正，我们先划重点：mybatis快速入门,mybatis详解,mybatis使用详解，下面大家一起来学习吧。
一、使用maven加载依赖
加载了连接数据库的依赖、mybatis的依赖以及lombok的依赖
<dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.4</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.12</version> </dependency>
二、建库、建表
三、配置MyBatis的配置文件（conf.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>
<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/数据库名字?/useUnicode=true&characterEncoding=utf8&useSSL=false" />
<property name="username" value="root" />
<property name="password" value="数据库密码" />
</dataSource>
</environment>
</environments>
</configuration>
四、定义表所对应的实体类
@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
private Integer uid;
private String uname;
private String password;
}
五、定义操作表的sql的映射文件xxxMapper.xml
见名知意，操作的user表，所以映射文件也命名为了userMapper.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">
<!--tuser是我自己定的名字-->
<mapper namespace="tuser">
<!--id自己设置，等会调用方法名使用，resultType查询结果类型-->
<select id="getUserById" resultType="com.hongda.space.entity.User">
<!--sql语句，#{}是参数格式，注意字段要与实体类属性一致-->
select * from t_user where uid=#{uid}
</select>
<!--parameterType参数类型-->
<insert id="insertUser" parameterType="com.hongda.space.entity.User">
insert into t_user(uname,password) values(#{uname},#{password});
</insert>
</mapper>
六、在Mybatis配置文件中添加映射文件
将编写好的userMapper.xml添加到mybatis.xml配置文件，下方
<?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/数据库名字?/useUnicode=true&characterEncoding=utf8&useSSL=false" />
<property name="username" value="root" />
<property name="password" value="数据库密码" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="mapper/userMapper.xml"/>
</mappers>
</configuration>
七、编写增删改查代码测试
import com.hongda.space.entity.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.IOException;
import java.io.Reader;
/**
* @ClassName Test01
* @Description TODO
* @Author whd
* @Date 2021/3/19 14:45
*/
public class Test01 {
public static void main(String[] args) throws IOException {
//1.读取配置文件
Reader reader = Resources.getResourceAsReader("conf.xml");
//2.获取sqlSessionFactory
SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);
//3.获取sqlsession对象 执行sql
SqlSession session = sessionFactory.openSession();
//4.执行sql
User user = session.selectOne("tuser.getUserById", 1);
System.out.println(user);
int i = session.insert("tuser.insertUser",new User(null, "小刘", "4545"));
System.out.println(i+"------------");
session.commit();
}
}
结果：
一些错误
编写中可能碰到的错误
1.Mapped Statements collection does not contain…
2.The server time zone value'XXXXXXXXX' is…
在Mybatis配置文件中的jdbc连接地址后面拼接serverTimezone=Asia/Shanghai
总结
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