Make hibernate ignore class variables that are not mapped
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?!
Answer
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.