Springboot整合mysql 5.7 实现增删改查_springboot2 mysql5.7

出现 Cannot resolve class or package ‘mysql’处理方法
https://blog.csdn.net/zhouhan_0509/article/details/127319458

这个是因为连接mysql的版本的关系，cj是8.0的

Failed to obtain JDBC Connection； nested exception is com.mysql.cj.jdbc.exceptions.CommunicationsExc

https://blog.csdn.net/RavenWE/article/details/121482923

useSSL=false和true的区别
https://blog.csdn.net/sungancd/article/details/119183605

<?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>kafka</artifactId>
    <version>1.0-SNAPSHOT</version>

    <!--springboot启动类依赖导入-->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.2.RELEASE</version>
        <relativePath/>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.71</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.1</version>
        </dependency>

    </dependencies>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

</project>
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SpringBoot中Server层以及Mapper层常用注解

SpringBoot项目连接MySQL数据库

IDEA创建Mapper.xml文件

mapper层

批量修改或者新增

@Controller
@RequestMapping("/hello")
public class Test1Controller {

    @Autowired
    private OrderServiceImpl orderServiceImpl;

    @RequestMapping("/h")
    public void test(){
       // System.out.println(orderService.findById());

        /*Order order = new Order();
        order.setOrderName("圣女果");
        order.setOrderId(4L);
        order.setFeature("贵且好吃");
        System.out.println(order);
        //orderService.updateById(order);
        System.out.println(orderServiceImpl.saveOrUpdate(order));*/

        List <Order> orderList = new ArrayList<>();
        orderList.add(new Order().setOrderId(1L).setOrderName("批量修改"));
        orderList.add(new Order().setOrderId(5L).setOrderName("新增水果").setNumber("100005").setFeature("批量新增或者修改测试"));
        System.out.println(orderServiceImpl.saveOrUpdateBatch(orderList));
    }
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