SpringBoot+MyBatisPlus

        Spring Boot 结合 MyBatis Plus 是一种常见的 Java 后端开发框架组合，能够快速构建高性能、易于维护的 CRUD 应用程序。以下是 Spring Boot 集成 MyBatis Plus 的基本步骤 

一、快速体验

注意：下面版本 idea2020 + SpringBoot2.* + MyBatis-Plus3.4之前的版本

1. 创建Maven项目

​ 选择使用阿里云

选择依赖：

生成的pom.xml 关键依赖：

<dependencies>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.4.2</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
        <exclusions>
            <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
</dependencies>

2. 配置文件

默认生成的效果：

# 应用名称
spring.application.name=springboot-mybatisplus
# 数据库驱动：
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
# 数据源名称
spring.datasource.name=defaultDataSource
# 数据库连接地址
spring.datasource.url=jdbc:mysql://localhost:3306/blue?serverTimezone=UTC
# 数据库用户名&密码：
spring.datasource.username=***
spring.datasource.password=***

我们只需修改密码、用户名、数据库就可以了

注意：

现在的版本在使用SpringBoot 初始化工具已经不能选择 mybatis-plus 依赖，也不再生成上面的配置了

自己配置 application.yml:

spring:
  datasource:
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/booksys
  sql:
    init:
      data-locations: classpath:db/data.sql    # 插入记录的数据库脚本
      schema-locations: classpath:db/schema.sql # 建库建表的数据库脚本
      mode: embedded  # 如果是嵌入式数据库 则执行
#      mode: never    # 都不执行
#      mode: always   # 总是执行sql脚本

其中的初始化数据库模式区分三种： embedded 只适用于嵌入式数据库会执行脚本

3. 编写POJO

@Data
public class Book {
    private Integer bookid;
    private String bookname;
    private Float price;
    private Date pubdate;
    private String author;
}

4. 编写接口继承BaseMapper

/**
 * 接口
 * 注意：注解 @Mapper
 */
@Mapper
public interface IBookDao extends BaseMapper<Book> {
}

5. 测试

@SpringBootTest
class SpringbootMybatisplusApplicationTests {

    @Autowired
    private IBookDao bookDao;
    @Test
    void contextLoads() {
        Integer count = bookDao.selectCount(null);
        System.out.println(count);

        bookDao.selectList(null).forEach(System.out::println);
    }

}

6. 版本组合

注意下面两种组合版本：

springboot3 必须要和 Mybatis-Plus3.5以上版本

• idea2022 + springboot2.7.6 + MybatisPlus3.4.2
• idea2022 + springboot3.0.5 + MybatisPlus3.5.3

组合一：idea2022 + springboot2.7.5 + MybatisPlus3.4.2

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.6</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.wdzl</groupId>
    <artifactId>springboot2_MybatisPlus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot2_MybatisPlus</name>
    <description>springboot2_MybatisPlus</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.2</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

组合二：idea2022 + springboot3.0.5 + MybatisPlus3.5.3

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.wdzl</groupId>
    <artifactId>springboot3_MybatisPlus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot3_MybatisPlus</name>
    <description>springboot3_MybatisPlus</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.baomidou/mybatis-plus-boot-starter -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.3</version>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>