//$Id: Criteria.java 9116 2006-01-23 21:21:01Z steveebersole $
package org.hibernate;
import java.util.List;
import org.hibernate.criterion.CriteriaSpecification;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Projection;
import org.hibernate.transform.ResultTransformer;
/**
* <tt>Criteria</tt> is a simplified API for retrieving entities
* by composing <tt>Criterion</tt> objects. This is a very
* convenient approach for functionality like "search" screens
* where there is a variable number of conditions to be placed
* upon the result set.<br>
* <br>
* The <tt>Session</tt> is a factory for <tt>Criteria</tt>.
* <tt>Criterion</tt> instances are usually obtained via
* the factory methods on <tt>Restrictions</tt>. eg.
* <pre>
* List cats = session.createCriteria(Cat.class)
* .add( Restrictions.like("name", "Iz%") )
* .add( Restrictions.gt( "weight", new Float(minWeight) ) )
* .addOrder( Order.asc("age") )
* .list();
* </pre>
* You may navigate associations using <tt>createAlias()</tt> or
* <tt>createCriteria()</tt>.
* <pre>
* List cats = session.createCriteria(Cat.class)
* .createCriteria("kittens")
* .add( Restrictions.like("name", "Iz%") )
* .list();
* </pre>
* <pre>
* List cats = session.createCriteria(Cat.class)
* .createAlias("kittens", "kit")
* .add( Restrictions.like("kit.name", "Iz%") )
* .list();
* </pre>
* You may specify projection and aggregation using <tt>Projection</tt>
* instances obtained via the factory methods on <tt>Projections</tt>.
* <pre>
* List cats = session.createCriteria(Cat.class)
* .setProjection( Projections.projectionList()
* .add( Projections.rowCount() )
* .add( Projections.avg("weight") )
* .add( Projections.max("weight") )
* .add( Projections.min("weight") )
* .add( Projections.groupProperty("color") )
* )
* .addOrder( Order.asc("color") )
* .list();
* </pre>
*
* @see Session#createCriteria(java.lang.Class)
* @see org.hibernate.criterion.Restrictions
* @see org.hibernate.criterion.Projections
* @see org.hibernate.criterion.Order
* @see org.hibernate.criterion.Criterion
* @see org.hibernate.criterion.Projection
* @see org.hibernate.criterion.DetachedCriteria a disconnected version of this API
* @author Gavin King
*/
public interface Criteria extends CriteriaSpecification {
/**
* Get the alias of the entity encapsulated by this criteria instance.
*
* @return The alias for the encapsulated entity.
*/
public String getAlias();
/**
* Used to specify that the query results will be a projection (scalar in
* nature). Implicitly specifies the {@link #PROJECTION} result transformer.
* <p/>
* The individual components contained within the given
* {@link Projection projection} determines the overall "shape" of the
* query result.
*
* @param projection The projection representing the overall "shape" of the
* query results.
* @return this (for method chaining)
*/
public Criteria setProjection(Projection projection);
/**
* Add a {@link Criterion restriction} to constrain the results to be
* retrieved.
*
* @param criterion The {@link Criterion criterion} object representing the
* restriction to be applied.
* @return this (for method chaining)
*/
public Criteria add(Criterion criterion);
/**
* Add an {@link Order ordering} to the result set.
*
* @param order The {@link Order order} object representing an ordering
* to be applied to the results.
* @return this (for method chaining)
*/
public Criteria addOrder(Order order);
/**
* Specify an association fetching strategy for an association or a
* collection of values.
*
* @param associationPath a dot seperated property path
* @param mode The fetch mode for the referenced association
* @return this (for method chaining)
*/
public Criteria setFetchMode(String associationPath, FetchMode mode) throws HibernateException;
/**
* Set the lock mode of the current entity
*
* @param lockMode The lock mode to be applied
* @return this (for method chaining)
*/
public Criteria setLockMode(LockMode lockMode);
/**
* Set the lock mode of the aliased entity
*
* @param alias The previously assigned alias representing the entity to
* which the given lock mode should apply.
* @param lockMode The lock mode to be applied
* @return this (for method chaining)
*/
public Criteria setLockMode(String alias, LockMode lockMode);
/**
* Join an association, assigning an alias to the joined association.
* <p/>
* Functionally equivalent to {@link #createAlias(String, String, int)} using
* {@link #INNER_JOIN} for the joinType.
*
* @param associationPath A dot-seperated property path
* @param alias The alias to assign to the joined association (for later reference).
* @return this (for method chaining)
*/
public Criteria createAlias(String associationPath, String alias) throws HibernateException;
/**
* Join an association using the specified join-type, assigning an alias
* to the joined association.
* <p/>
* The joinType is expected to be one of {@link #INNER_JOIN} (the default),
* {@link #FULL_JOIN}, or {@link #LEFT_JOIN}.
*
* @param associationPath A dot-seperated property path
* @param alias The alias to assign to the joined association (for later reference).
* @param joinType The type of join to use.
* @return this (for method chaining)
*/
public Criteria createAlias(String associationPath, String alias, int joinType) throws HibernateException;
/**
* Create a new <tt>Criteria</tt>, "rooted" at the associated entity.
* <p/>
* Functionally equivalent to {@link #createCriteria(String, int)} using
* {@link #INNER_JOIN} for the joinType.
*
* @param associationPath A dot-seperated property path
* @return the created "sub criteria"
*/
public Criteria createCriteria(String associationPath) throws HibernateException;
/**
* Create a new <tt>Criteria</tt>, "rooted" at the associated entity, using the
* specified join type.
*
* @param associationPath A dot-seperated property path
* @param joinType The type of join to use.
* @return the created "sub criteria"
*/
public Criteria createCriteria(String associationPath, int joinType) throws HibernateException;
/**
* Create a new <tt>Criteria</tt>, "rooted" at the associated entity,
* assigning the given alias.
* <p/>
* Functionally equivalent to {@link #createCriteria(String, String, int)} using
* {@link #INNER_JOIN} for the joinType.
*
* @param associationPath A dot-seperated property path
* @param alias The alias to assign to the joined association (for later reference).
* @return the created "sub criteria"
*/
public Criteria createCriteria(String associationPath, String alias) throws HibernateException;
/**
* Create a new <tt>Criteria</tt>, "rooted" at the associated entity,
* assigning the given alias and using the specified join type.
*
* @param associationPath A dot-seperated property path
* @param alias The alias to assign to the joined association (for later reference).
* @param joinType The type of join to use.
* @return the created "sub criteria"
*/
public Criteria createCriteria(String associationPath, String alias, int joinType) throws HibernateException;
/**
* Set a strategy for handling the query results. This determines the
* "shape" of the query result.
*
* @param resultTransformer The transformer to apply
* @return this (for method chaining)
*
* @see #ROOT_ENTITY
* @see #DISTINCT_ROOT_ENTITY
* @see #ALIAS_TO_ENTITY_MAP
* @see #PROJECTION
*/
public Criteria setResultTransformer(ResultTransformer resultTransformer);
/**
* Set a limit upon the number of objects to be retrieved.
*
* @param maxResults the maximum number of results
* @return this (for method chaining)
*/
public Criteria setMaxResults(int maxResults);
/**
* Set the first result to be retrieved.
*
* @param firstResult the first result to retrieve, numbered from <tt>0</tt>
* @return this (for method chaining)
*/
public Criteria setFirstResult(int firstResult);
/**
* Set a fetch size for the underlying JDBC query.
*
* @param fetchSize the fetch size
* @return this (for method chaining)
*
* @see java.sql.Statement#setFetchSize
*/
public Criteria setFetchSize(int fetchSize);
/**
* Set a timeout for the underlying JDBC query.
*
* @param timeout The timeout value to apply.
* @return this (for method chaining)
*
* @see java.sql.Statement#setQueryTimeout
*/
public Criteria setTimeout(int timeout);
/**
* Enable caching of this query result, provided query caching is enabled
* for the underlying session factory.
*
* @param cacheable Should the result be considered cacheable; default is
* to not cache (false).
* @return this (for method chaining)
*/
public Criteria setCacheable(boolean cacheable);
/**
* Set the name of the cache region to use for query result caching.
*
* @param cacheRegion the name of a query cache region, or <tt>null</tt>
* for the default query cache
* @return this (for method chaining)
*
* @see #setCacheable
*/
public Criteria setCacheRegion(String cacheRegion);
/**
* Add a comment to the generated SQL.
*
* @param comment a human-readable string
* @return this (for method chaining)
*/
public Criteria setComment(String comment);
/**
* Override the flush mode for this particular query.
*
* @param flushMode The flush mode to use.
* @return this (for method chaining)
*/
public Criteria setFlushMode(FlushMode flushMode);
/**
* Override the cache mode for this particular query.
*
* @param cacheMode The cache mode to use.
* @return this (for method chaining)
*/
public Criteria setCacheMode(CacheMode cacheMode);
/**
* Get the results.
*
* @return The list of matched query results.
*/
public List list() throws HibernateException;
/**
* Get the results as an instance of {@link ScrollableResults}
*
* @return The {@link ScrollableResults} representing the matched
* query results.
*/
public ScrollableResults scroll() throws HibernateException;
/**
* Get the results as an instance of {@link ScrollableResults} based on the
* given scroll mode.
*
* @param scrollMode Indicates the type of underlying database cursor to
* request.
* @return The {@link ScrollableResults} representing the matched
* query results.
*/
public ScrollableResults scroll(ScrollMode scrollMode) throws HibernateException;
/**
* Convenience method to return a single instance that matches
* the query, or null if the query returns no results.
*
* @return the single result or <tt>null</tt>
* @throws HibernateException if there is more than one matching result
*/
public Object uniqueResult() throws HibernateException;
}
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