MyBatisPlus--通用枚举

向右看齐 2021-08-26 16:21 727阅读 0赞

### 通用枚举 ###

MyBatisPlus解决了繁琐的配置，让MyBatis更优雅的适用枚举属性。

### 配置枚举类扫描包 ###

# 配置枚举扫描包
    mybatis-plus.type-enums-package=psers.zhang.demo.enums

### 枚举类(实现IEnum<T>) ###

public enum SexEnum implements IEnum<Integer> { 
    
        MALE(1, "男"),
        FEMALE(0, "女");
    
        private int value;
        private String desc;
    
        SexEnum(int value, String desc) { 
            this.value = value;
            this.desc = desc;
        }
    
        @Override
        public Integer getValue() { 
            return this.value;
        }
    
        @Override
        public String toString() { 
            return this.desc;
        }
    }

### 表结构 ###

![在这里插入图片描述][20200212132735591.png]

### 实体类 ###

@Data
    @NoArgsConstructor
    @AllArgsConstructor
    @TableName("tb_user")
    public class User extends Model<User> { 
    
        //指定主键为自增
        @TableId(type = IdType.AUTO)
        private Long id;
    
        //指定数据表中字段名
        @TableField(value = "user_name")
        private String userName;
    
        @TableField(fill = FieldFill.INSERT)
        private String password;
        private String name;
        private Integer age;
        private String email;
    
        //逻辑删除字段： 0，未删除； 1，已删除
        @TableLogic //标记为逻辑删除字段
        private Integer deleted;
    
    
        //性别，枚举类型：1，男； 0，女
        private SexEnum sex;
    
    
        //指定该字段在表中是不存在的
        @TableField(exist = false)
        private String address;
    }

### 测试 ###

插入数据：自动将枚举映射为字段值

@Test
        public void testInsert(){ 
            User user = new User();
            user.setEmail("123456@qq.com");
            user.setAge(18);
            user.setName("diaochan");
            user.setUserName("貂蝉");
            user.setPassword("123456");
            user.setSex(SexEnum.FEMALE);
            user.setDeleted(0);
            //返回受影响的行数
            int rows = userMapper.insert(user);
            System.out.println(rows);
    
            //获取自增长后的id值,MP会自动回填自增后的id
            System.out.println(user.getId());
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70]

查询：自动将字段值映射为枚举值

@Test
        public void testSelectList(){ 
            List<User> users = userMapper.selectList(null);
            for (User u : users)
                System.out.println(u);
        }

控制台打印：

Execute SQL：
        SELECT
            id,
            user_name,
            password,
            name,
            age,
            email,
            deleted,
            sex 
        FROM
            tb_user 
        WHERE
            deleted=0
    
    User(id=4, userName=zhaoliu, password=123456, name=赵六, age=48, email=test4@qq.com, deleted=0, sex=男, address=null)
    User(id=5, userName=小强, password=88888, name=xiaoqiang, age=30, email=123456@qq.com, deleted=0, sex=男, address=null)
    User(id=6, userName=貂蝉, password=123456, name=diaochan, age=18, email=123456@qq.com, deleted=0, sex=女, address=null)

[20200212132735591.png]: /images/20210813/b34b59f9282a415789f3fe70cb3b9694.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70]: /images/20210813/2d8019d33569451bb200fa8603252cdc.png