I am using Hibernate 3.5.6 and MySQL 5.1. I have 3 classes: Item, Attribute, AttributeValue. They are related to each other in a one-to-many relationship, and I get all the attributes for this element. But I do not get AttributeValues for this attribute. I see no exceptions or errors, and the data in the tables looks good, which means that the data insert went well.
I tried different strategies for the FetchMode attribute map of AttributeValues, but the result is always empty.
What did I miss?
Here are the classes:
@Entity @Table(name = "Item") public class Item implements Serializable { private static final long serialVersionUID = 1L; @Id private String serialNumber; @OneToMany(fetch = FetchType.EAGER, mappedBy = "item", cascade = CascadeType.ALL) @Fetch(value = FetchMode.SELECT)
@Entity @Table(name = "Attribute", uniqueConstraints = {@UniqueConstraint(columnNames = {"item_serialNumber", "name"})}) public class Attribute implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Integer id; @ManyToOne(cascade = CascadeType.ALL) private Item item; @Column(nullable = false) private String name; @OneToMany(fetch = FetchType.EAGER, mappedBy = "value", cascade = CascadeType.ALL) @Fetch(value = FetchMode.SELECT) @MapKey(name = "value") private Map<String, AttributeValue> values = new HashMap<String, AttributeValue>(); protected Attribute() { super(); } public Attribute(String name) { super(); this.name = name; } public Integer getId() { return id; } protected void setId(Integer id) { this.id = id; } public Item getItem() { return item; } public void setItem(Item item) { this.item = item; } public String getName() { return name; } protected void setName(String newName) { this.name = newName; } public Map<String, AttributeValue> getValues() { return values; } public void setValues(Map<String, AttributeValue> values) { this.values = values; } }
@Entity @Table(name = "AttributeValue", uniqueConstraints = {@UniqueConstraint(columnNames = {"attribute_id", "value"})}) public class AttributeValue implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Integer id; @Column private String value; @ManyToOne(cascade = CascadeType.ALL) private Attribute attribute; protected AttributeValue() { super(); } public AttributeValue(String value) { this.value = value; } protected Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getValue() { return value; } protected void setValue(String value) { this.value = value; } public Attribute getAttribute() { return attribute; } public void setAttribute(Attribute attribute) { this.attribute = attribute; } }
And here is the SQL base table:
-- -- Table structure for table `Attribute` -- CREATE TABLE `Attribute` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, `item_serialNumber` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`), UNIQUE KEY `item_serialNumber` (`item_serialNumber`,`name`), KEY `FK7839CA7C252F491C` (`item_serialNumber`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; -- -------------------------------------------------------- -- -- Table structure for table `Item` -- CREATE TABLE `Item` ( `id` int(11) NOT NULL AUTO_INCREMENT, `serialNumber` varchar(255) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY `serialNumber` (`serialNumber`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; -- -------------------------------------------------------- -- -- Table structure for table `AttributeValue` -- CREATE TABLE `AttributeValue` ( `id` int(11) NOT NULL AUTO_INCREMENT, `value` varchar(255) DEFAULT NULL, `attribute_id` int(11) DEFAULT NULL, PRIMARY KEY (`id`), UNIQUE KEY `attribute_id` (`attribute_id`,`value`), KEY `FK4C1BA6C69CA0A39A` (`attribute_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; -- -- Constraints for dumped tables -- -- -- Constraints for table `Attribute` -- ALTER TABLE `Attribute` ADD CONSTRAINT `FK7839CA7C252F491C` FOREIGN KEY (`item_serialNumber`) REFERENCES `Item` (`serialNumber`); -- -- Constraints for table `AttributeValue` -- ALTER TABLE `AttributeValue` ADD CONSTRAINT `FK4C1BA6C69CA0A39A` FOREIGN KEY (`attribute_id`) REFERENCES `Attribute` (`id`);