使休眠忽略未映射的类变量 [英] Make hibernate ignore class variables that are not mapped

问题描述

我认为 hibernate 只考虑用 @Column 注释的类变量.但奇怪的是，今天当我添加一个变量(它没有映射到任何列，只是我在类中需要的一个变量)时，它试图将该变量作为列名包含在 select 语句中并抛出错误 -

I thought hibernate takes into consideration only class variables that are annotated with @Column. But strangely today when I added a variable (that is not mapped to any column, just a variable i need in the class), it is trying to include that variable in the select statement as a column name and throws the error -

字段列表"中的未知列team1_.agencyName"

Unknown column 'team1_.agencyName' in 'field list'

我的班级 -

@Entity
@Table(name="team")
public class Team extends BaseObject implements Serializable {

@Id  @GeneratedValue(strategy=GenerationType.AUTO)
private Long id;

@Column(length=50)
private String name;

@Column(length=10)
private String code;

@Column(name = "agency_id")
private Long agencyId;

private String agencyName; //note: not annotated.

}

仅供参考...我在另一个具有多对多映射的类中使用上述类

FYI...I use the above class in another class with many to many mapping

@ManyToMany(fetch = FetchType.EAGER) 
@JoinTable(
        name="user_team",
        joinColumns = { @JoinColumn( name="user_id") },
        inverseJoinColumns = @JoinColumn( name="team_id")
)    
public Set<Team> getTeams() {
    return teams;
}

为什么会这样?！

推荐答案

JPA 将使用该类的所有 属性，除非您专门用 @Transient 标记它们:

JPA will use all properties of the class, unless you specifically mark them with @Transient:

@Transient
private String agencyName;

@Column 注释纯粹是可选的，它可以让您覆盖自动生成的列名.此外，@Column 的length 属性只在自动生成表定义时使用，对运行时没有影响.

The @Column annotation is purely optional, and is there to let you override the auto-generated column name. Furthermore, the length attribute of @Column is only used when auto-generating table definitions, it has no effect on the runtime.

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