springboot整合MybatisPlus+MySQL

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一、准备

docker部署MySQL：参考docker安装各个组件的命令

二、主要工作

• 准备数据库环境：新建数据库sd，再导入sql脚本
• 引入MybatisPlus和MySQL依赖
• 修改配置文件bootstrap.yml
• 使用Mybatisplus

三、具体步骤

3.1 准备数据库环境

CREATE TABLE `t_product` (`id` bigint NOT NULL AUTO_INCREMENT COMMENT '主键',`name` varchar(64) NOT NULL COMMENT '名称',`price` int NOT NULL COMMENT '价格',PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=14787164048663 DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci COMMENT='商品表';CREATE TABLE `t_order` (`id` bigint NOT NULL AUTO_INCREMENT COMMENT '主键',`amount` int NOT NULL COMMENT '金额',`user_id` bigint NOT NULL COMMENT '创建订单的用户id',`create_time` datetime NOT NULL DEFAULT now() COMMENT '创建时间',PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=21787164048663 DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci COMMENT='订单表';insert into t_product values(null,"铅笔",3);
insert into t_product values(null,"橡皮",1);
insert into t_product values(null,"钢笔",50);
insert into t_product values(null,"文具袋",20);insert into t_order(`amount`,`user_id`) values(99,10001);
insert into t_order(`amount`,`user_id`) values(88,10002);
insert into t_order(`amount`,`user_id`) values(77,10003);
insert into t_order(`amount`,`user_id`) values(66,10004);

3.20 pre引入依赖

先改变一下项目结构，给product-service和order-service加一个父模块sd-service

• 新建一个service-demo的子模块sd-service，删掉多余文件，pom文件中打包类型为pom，并且\<modules>部分把product-service和order-service放进去
• 删掉service-demo中的\<modules>部分中的product-service和order-service
• 在product-service和order-service的pom文件中\<parent>设置为sd-service
• 将product-service和order-service的模块目录，分别移动到sd-service下
• 结构修改完成后，可以将product-service和order-service模块的共同都有的依赖移动到sd-service，比如nacos，lombok，sentinel，web这些。再重新加载所有Maven工程

修改完成后结构如下

3.2 引入依赖

在sd-service中引入依赖，product-service和order-service自动会继承

        <!--mybatis-plus--><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId></dependency><!--2.7.8版本mysql-connector-java -> com.mysql:mysql-connector-j 并删除 mysql-connector-java 依赖管理--><!--mysql--><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId> </dependency>

3.3 bootstrap.yml配置mybatisplus

# 数据源
spring:datasource:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://192.168.200.131:3306/sd?serverTimezone=GMT%2B8username: rootpassword: root# mybatisplus配置
mybatis-plus:# xml扫描，多个目录用逗号或者分号分隔（告诉 Mapper 所对应的 XML 文件位置）mapper-locations: classpath:mapper/*.xml# 以下配置均有默认值,可以不设置#  global-config:#    db-config:#      #主键类型 AUTO:"数据库ID自增" INPUT:"用户输入ID",ID_WORKER:"全局唯一ID (数字类型唯一ID)", UUID:"全局唯一ID UUID";#      id-type: auto#      #字段策略 IGNORED:"忽略判断"  NOT_NULL:"非 NULL 判断")  NOT_EMPTY:"非空判断"#      field-strategy: NOT_EMPTY#      #数据库类型#      db-type: MYSQLconfiguration:# 是否开启自动驼峰命名规则映射:从数据库列名到Java属性驼峰命名的类似映射map-underscore-to-camel-case: true# 如果查询结果中包含空值的列，则 MyBatis 在映射的时候，不会映射这个字段# call-setters-on-nulls: true# 这个配置会将执行的sql打印出来，在开发或测试的时候可以用log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

3.40 pre引入service、mapper

• 把product相关类的id从Integer改成Long,并改相关的controller
• 引入返回响应体类R<T>

/*** 响应信息主体** @author ruoyi*/
public class R<T> implements Serializable
{private static final long serialVersionUID = 1L;/** 成功 */private static final int SUCCESS = 200;/** 失败 */private static final int FAIL = 500;private int code;private String msg;private T data;public static <T> R<T> ok(){return restResult(null, SUCCESS, null);}public static <T> R<T> ok(T data){return restResult(data, SUCCESS, null);}public static <T> R<T> ok(T data, String msg){return restResult(data, SUCCESS, msg);}public static <T> R<T> fail(){return restResult(null, FAIL, null);}public static <T> R<T> fail(String msg){return restResult(null, FAIL, msg);}public static <T> R<T> fail(T data){return restResult(data, FAIL, null);}public static <T> R<T> fail(T data, String msg){return restResult(data, FAIL, msg);}public static <T> R<T> fail(int code, String msg){return restResult(null, code, msg);}private static <T> R<T> restResult(T data, int code, String msg){R<T> apiResult = new R<>();apiResult.setCode(code);apiResult.setData(data);apiResult.setMsg(msg);return apiResult;}public int getCode(){return code;}public void setCode(int code){this.code = code;}public String getMsg(){return msg;}public void setMsg(String msg){this.msg = msg;}public T getData(){return data;}public void setData(T data){this.data = data;}public static <T> Boolean isError(R<T> ret){return !isSuccess(ret);}public static <T> Boolean isSuccess(R<T> ret){return R.SUCCESS == ret.getCode();}
}

3.4 引入实体类、service、mapper

• 在com.hdl.product.pojos包新建包po

@Data
@TableName("t_product")
public class Product {@TableId(value = "id",type = IdType.AUTO)Long id;@TableField(value = "name")String name;@TableField(value = "price")Integer price;
}

• 在com.hdl.product包下新建包service和servicce.impl

// com.hdl.product.service包下
public interface ProductService extends IService<Product> {
}// com.hdl.product.service.impl包下
@Service
public class ProductServiceImpl extends ServiceImpl<ProductMapper, Product> implements ProductService {
}

• 在com.hdl.product包下新建包mapper

@Mapper
public interface ProductMapper extends BaseMapper<Product> {
}

四、测试

修改controller

    @GetMapping("/testmp")public R testmp(){List<Product> list = productService.list();return R.ok(list);}

测试

控制台打印出了日志

目录结构

五、wrapper,分页相关语法

Springboot集成MybatisPlus以及常用语句、分页