Mybatis学习笔记

<dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-thymeleaf</artifactId>  
    </dependency> 
        
    <dependency>  
            <groupId>mysql</groupId>  
            <artifactId>mysql-connector-java</artifactId>  
    </dependency>  
        
    <dependency>  
            <groupId>org.mybatis.spring.boot</groupId>  
            <artifactId>mybatis-spring-boot-starter</artifactId>  
            <version>1.3.0</version>  
    </dependency>

    @RestController
public class LibrarianController {
    
    @Autowired
    private LibrarianService librarianService;
    
    @GetMapping("/getLibrarian")
    public Librarian getALibrarianInfo(int id) {
        //System.out.println("test :id: "+id);
        return librarianService.selectLibrarian(id);
    }
}

@Service
public class LibrarianServiceImpl implements LibrarianService{
    
    @Autowired
    private LibrarianMapper librarianMapper;
    
    @Override
    public Librarian selectLibrarian(int id) {
        // TODO Auto-generated method stub
        return librarianMapper.selectLibrarian(id);
    }
}

package com.example.dao;


import org.apache.ibatis.annotations.Mapper;

import com.example.entity.Librarian;

@Mapper
public interface LibrarianMapper {
    Librarian selectLibrarian(int id);
}

我用了@Mapper是可以的，网上说也可用@Repository 一个mybatis的，一个 spring的

<?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="com.example.springbootdemo.dao.HelloMapper">




    <select id="getUserNameById" parameterType="INTEGER" resultType="String">
        select username
        from user
        where 1=1
            and id = #{id,jdbcType=INTEGER}
    </select>



</mapper>

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/mg?serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root

mybatis.type-aliases-package=com.example.springbootdemo.pojo
mybatis.mapperLocations=classpath:mapper/*.xml

踩坑记录：

1 记得需要 url选择时区， 为 UTC才可以，需要配置 pojo位置和 mapper的位置

出错有没有注释掉zookeeper，一直报错
2  mybatis 配置基本类型，可全大写，首字母大写，全小写都可以
3
he server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver

4 一般数据库连接 后缀

?serverTimezone=GMT%2B8&zeroDateTimeBehavior=convertToNull