生成的实体带@Column注释的是哪个?
时间: 2024-03-23 15:36:50 浏览: 66
@Column注释是JPA(Java Persistence API)规范中的注释,用于将Java实体类属性与数据库表字段进行映射。它通常用于ORM(Object-Relational Mapping)框架中,比如Hibernate、EclipseLink等。
因此,如果您使用JPA规范的ORM框架,则生成的实体类应该带有@Column注释。在Java实体类中,使用@Column注释可以指定数据库表中与该属性对应的列的名字、类型、长度、是否可为空等属性,代码示例如下:
```java
@Entity
@Table(name = "user")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "username", nullable = false, length = 20)
private String username;
@Column(name = "password", nullable = false, length = 50)
private String password;
// getter and setter
}
```
在上面的代码中,@Column注释指定了username属性对应的数据库表列名为username,类型为VARCHAR,长度为20,不允许为空;password属性对应的数据库表列名为password,类型为VARCHAR,长度为50,不允许为空。
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