JPA - need help with query

[Robert Tomson]

hi, i am working on recreating tree from database table,



what i need to do is to select all items where parentIndex is null

so in mysql i can do : SELECT * FROM `treemenu` WHERE parentIndex IS NULL

how should query look like in jpa to get same results ?

"SELECT t FROM TreeMenu t WHERE t.parentIndex IS NULL" gives me 'unknown state or association field [parentIndex]'

[Joe carco]

please show us your entity code and its mappings / annotations

[Robert Tomson]

it was automatically generated by netBeans

@Entity
@Table(name = "treemenu")
public class TreeMenu implements Serializable {
	private static final long serialVersionUID = 1L;
	@Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "itemIndex")
	private Integer itemIndex;
	@Basic(optional = false)
    @Column(name = "title")
	private String title;
	@OneToMany(mappedBy = "treeMenu")
	private Collection<TreeMenu> treeMenuCollection;
	@JoinColumn(name = "parentIndex", referencedColumnName = "itemIndex")
    @ManyToOne
	private TreeMenu treeMenu;

[Joe carco]

Are you using JPA Query Language or Native Query Language?

[Joe carco]

If you're using JPQL, try this

select t from TreeMenu t where t.treeMenu IS NULL

in your query youre using a database column. I assume you are using JPQL, there the atabase column "parentindex" correctly causes that exception

[Robert Tomson]

thank you very much , its working, haha now when i know the answer its seams logical :P