Hibernate is not creating unique constraint specified in @JoinTable

Description

Hi,

When using join table for many to many relationship i have specified unique constraint, but the same has not been created in Database.

Here is my entity definition :-

@Cacheable
@Entity(name = "ImageGroup")
@Table(name = "\"image_group\"", indexes = {
		@Index(name = "\"img_grp_tenant_name_idx\"", columnList = "\"tenant\",\"name\""),
		@Index(name = "\"img_grp_tenant_idx\"", columnList = "\"tenant\"") }, uniqueConstraints = {
				@UniqueConstraint(name = "\"img_grp_tenant_name_uq\"", columnNames = { "\"tenant\"", "\"name\"" }), })
@SequenceGenerator(name = "image_group_id_sequence", sequenceName = "\"image_group_id_seq\"", initialValue = 1)
public class ImageGroupDO {

	/** The id. */
	@Id
	@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "image_group_id_sequence")
	@Column(name = "\"id\"")
	private long id;

	/** The name. */
	@NotNull
	@Size(min = 2, max = 255)
	@Column(name = "\"name\"", nullable = false, length = 255)
	private String name;

	/** The description. */
	@Size(max = 255)
	@Column(name = "\"description\"", length = 255)
	private String description;

	/** The active. */
	@NotNull
	@Column(name = "\"active\"", nullable = false)
	private boolean active;

	/** The tenant do. */
	@NotNull
	@ManyToOne(fetch = FetchType.EAGER, optional = false)
	@JoinColumn(name = "\"tenant\"", foreignKey = @ForeignKey(name = "\"img_grp_tenant_fk\""))
	private TenantDO tenantDo;

	/** The images. */
	@ManyToMany(fetch = FetchType.LAZY, cascade = { CascadeType.PERSIST, CascadeType.MERGE })
	@JoinTable(name = "\"image_group_image\"", joinColumns = 
		@JoinColumn(name = "\"image_group\"", referencedColumnName = "\"id\""), inverseJoinColumns = 
			@JoinColumn(name = "\"image\"", referencedColumnName = "\"id\""), 
			foreignKey = @ForeignKey(name = "\"img_grp_img_image_group_fk\""), 
			inverseForeignKey = @ForeignKey(name = "\"img_grp_img_image_fk\""), indexes = {
			@Index(name = "\"img_grp_img_image_group_fk_idx\"", columnList = "\"image_group\""),
			@Index(name = "\"img_grp_img_image_fk_idx\"", columnList = "\"image\"") }, uniqueConstraints = {
					@UniqueConstraint(name = "\"img_grp_img_img_grp_img_uq\"", columnNames = { "\"image_group\"",
							"\"image\"" }) })
	private Set<ImageDO> images = new HashSet<>();

	/** The created at. */
	@NotNull
	@Column(name = "\"created_at\"", nullable = false)
	private Date createdAt;

	/** The modified at. */
	@NotNull
	@Column(name = "\"modified_at\"", nullable = false)
	private Date modifiedAt;

	/**
	 * On create.
	 */
	@PrePersist
	protected void onCreate() {
		this.createdAt = new Date();
		this.modifiedAt = new Date();
	}

	/**
	 * On update.
	 */
	@PreUpdate
	protected void onUpdate() {
		this.modifiedAt = new Date();
	}

	/**
	 * Gets the id.
	 *
	 * @return the id
	 */
	public long getId() {
		return id;
	}

	/**
	 * Sets the id.
	 *
	 * @param id
	 *            the new id
	 */
	public void setId(long id) {
		this.id = id;
	}

	/**
	 * Gets the name.
	 *
	 * @return the name
	 */
	public String getName() {
		return name;
	}

	/**
	 * Sets the name.
	 *
	 * @param name
	 *            the new name
	 */
	public void setName(String name) {
		this.name = name;
	}

	/**
	 * Gets the description.
	 *
	 * @return the description
	 */
	public String getDescription() {
		return description;
	}

	/**
	 * Sets the description.
	 *
	 * @param description
	 *            the new description
	 */
	public void setDescription(String description) {
		this.description = description;
	}

	/**
	 * Checks if is active.
	 *
	 * @return true, if is active
	 */
	public boolean isActive() {
		return active;
	}

	/**
	 * Sets the active.
	 *
	 * @param active
	 *            the new active
	 */
	public void setActive(boolean active) {
		this.active = active;
	}

	/**
	 * Gets the tenant do.
	 *
	 * @return the tenant do
	 */
	public TenantDO getTenantDo() {
		return tenantDo;
	}

	/**
	 * Sets the tenant do.
	 *
	 * @param tenantDo
	 *            the new tenant do
	 */
	public void setTenantDo(TenantDO tenantDo) {
		this.tenantDo = tenantDo;
	}

	/**
	 * Gets the images.
	 *
	 * @return the images
	 */
	public Set<ImageDO> getImages() {
		return images;
	}

	/**
	 * Sets the images.
	 *
	 * @param images
	 *            the new images
	 */
	public void setImages(Set<ImageDO> images) {
		this.images = images;
	}

	/**
	 * Gets the created at.
	 *
	 * @return the created at
	 */
	public Date getCreatedAt() {
		return createdAt;
	}

	/**
	 * Sets the created at.
	 *
	 * @param createdAt
	 *            the new created at
	 */
	public void setCreatedAt(Date createdAt) {
		this.createdAt = createdAt;
	}

	/**
	 * Gets the modified at.
	 *
	 * @return the modified at
	 */
	public Date getModifiedAt() {
		return modifiedAt;
	}

	/**
	 * Sets the modified at.
	 *
	 * @param modifiedAt
	 *            the new modified at
	 */
	public void setModifiedAt(Date modifiedAt) {
		this.modifiedAt = modifiedAt;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object obj) {
		if (obj == null)
			return false;
		if (!(obj instanceof DataCenterDO))
			return false;
		ImageGroupDO imageGroupDO = ImageGroupDO.class.cast(obj);

		return this.id == imageGroupDO.getId();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode() {
		return new Long(id).intValue();
	}

}