> For the complete documentation index, see [llms.txt](https://sb-woms.gitbook.io/sb/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sb-woms.gitbook.io/sb/mybatisplus/basic-use.md).

# 基本使用

## 1. 特性1 - 自动生成id

先定义一个普通的po

```java
@Data
public class User {

    private Long id;

    private String name;

    private Integer age;

    private String email;
}
```

我们在保存对象的时候，并没有设置id主键

```java
User user = new User();

user.setAge(23);
user.setEmail("2332fw@qq.com");
user.setName("woms");
userMapper.insert(user);
```

mybatis-plus会自动帮我们生成id

```
DEBUG==>  Preparing: INSERT INTO user ( id, name, age, email ) VALUES ( ?, ?, ?, ? ) 
DEBUG==> Parameters: 1135178229880168450(Long), woms(String), 23(Integer), 2332fw@qq.com(String)
DEBUG<==    Updates: 1
```

## 特性2 - 下划线和驼峰自动转换

## 特性3 - 常用注解

主键、字段和表名的显式声明

```java
@Data
@TableName("user")
public class User {

    @TableId("id")
    private Long id;

    private String name;


    private Integer age;

    @TableField("email")
    private String email;
}
```

## 特性4 - 排除非表字段的三种方式

### 4.1 关键字 `transient` 标示的字段不参与序列化过程

```java
private transient String remark;
```

### 4.2 关键字 `static` 标示的字段

由于static字段属于类不属于对象，全局就一个，不符合我们的正常使用

### 4.3 `@TableField(exist = false)`

```java
@TableField(exist = false)
private String remark;
```