Hibernate Criteria restriction on a not loaded table

I'm trying to have a Criteria query to have a restriction on an entity that isn't loaded.

My mapping is all done via one-to-many relations.

For example, I'm trying to get the following SQL query using criteria:

SELECT {msg.*} FROM Messages AS msg  
WHERE msg.source_key IN 
  ( SELECT ds.unique_key FROM Data_Sources AS ds " +
    WHERE ds.source_type_key IN " +
       ( SELECT dst.unique_key FROM Data_Source_types AS dst " +
          WHERE unique_name = 'RequiredName' ) )

Thus, I want to get Messages, with a restriction that is set on an entity that is not fetched by Hibernate. Currently, the best I could get is:

Criteria crit = session.createCriteria( Message.class )
    .createAlias( "dataSource", "ds", CriteriaSpecification.INNER_JOIN )
    .createAlias( "ds.sourceType", "type" )
    .add( Restrictions.eq( "type.name", "HL7GatewayServer" ) )

However, this query also loads the dataSource and dataSourceType.

EDIT: My mapping:

MESSAGES:

@Entity
@Table(name="messages", schema="mySchema") 
@SequenceGenerator(name="sequence",sequenceName="mySchema.local_key_sequence")
public class Message
{
    @Id
    @Column(name = "unique_key")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequence")
    private long                     id;

    @JoinColumn(name = "source_key")
    @ManyToOne(targetEntity = DataSource.class, fetch = FetchType.LAZY)
    private DataSource               dataSource       = null;
    [...]
}

DATA_SOURCES:

@Entity
@Proxy(lazy = true)
@Table(name = "data_sources", schema = "mySchema")
@SequenceGenerator(name = "sequence", sequenceName = "mySchema.local_key_sequence")
public class DataSource
{
    @Id
    @Column(name = "unique_key")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequence")
    private long                      id;

    @JoinColumn(name = "source_type_key")
    @ManyToOne(targetEntity = DataSourceType.class, fetch = FetchType.LAZY)
    private DataSourceType            sourceType;

    @OneToMany(targetEntity = Message.class, mappedBy = "dataSource", fetch = FetchType.LAZY)
    private Set<Message>             messages = new HashSet<Message>();

    [...]
}

DATA_SOURCE_TYPE:

@Entity
@Table(name="data_source_types", schema="mySchema") 
@SequenceGenerator(name="sequence",sequenceName="mySchema.local_key_sequence")
public class DataSourceType
{
    @Id
    @Column(name="unique_key", unique=true,nullable=false)
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="sequence")
    private long id; 

    @OneToMany(targetEntity=DataSource.class, mappedBy="sourceType",fetch=FetchType.LAZY)
    private Set<DataSource> dataSources = new HashSet<DataSource>(0);

    [...]
}开发者_C百科

I managed to get this working in HQL, but is there a way to achieve this using Criteria?

try {

    crit = session.createCriteria(Message.class, "msg");
    crit.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
    // UPDATE
    // Add your criteria sub query or any ...
}

and add lazy='true'