让hibernate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，当我添加一个变量（未映射到任何列，只是我需要的类中的变量）时，它试图将该变量包含在select语句中作为列名并引发错误 -

'字段列表'中的未知列'team1_.agencyName'

My class -

  @Entity 
 @Table（name =team）
 public class Team extends BaseObject implements Serializable {
 
 @Id @GeneratedValue（strategy = GenerationType.AUTO）
 private Long id; 
 
 @Column（长度= 50）
私人字符串名称; 
 
 @Column（长度= 10）
私有字符串代码; 
 
 @Column（name =agency_id）
 private long agencyId; 
 
 private String agencyName; //注意：没有注释。 
 
 
  

仅供参考...我在另一类中使用上述类（

$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ =user_team，
joinColumns = {@JoinColumn（name =user_id）}，
inverseJoinColumns = @JoinColumn（name =team_id）
）
public Set<团队及GT; getTeams（）{
返回团队;
}

为什么会发生这种情况？！

属性，除非您使用 @Transient ：

  @Transient 
 private String agencyName; 
  

@Column 注释纯粹是可选的，并在那里让您覆盖自动生成的列名称。此外， @Column 的长度属性仅用于自动生成表定义时，它对运行时。

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 -

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

My class -

@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.

}

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;
}

Why is this happening?!

解决方案

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

@Transient
private String agencyName;

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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