//$Id: Query.java,v 1.17 2004/06/10 14:31:54 steveebersole Exp $
package net.sf.hibernate;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Calendar;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;

import net.sf.hibernate.type.Type;

/**
 * An object-oriented representation of a Hibernate query. A <tt>Query</tt>
 * instance is obtained by calling <tt>Session.createQuery()</tt>. This
 * interface exposes some extra functionality beyond that provided by
 * <tt>Session.iterate()</tt> and <tt>Session.find()</tt>:
 * <ul>
 * <li>a particular page of the result set may be selected by calling <tt>
 * setMaxResults(), setFirstResult()</tt>
 * <li>named query parameters may be used
 * <li>the results may be returned as an instance of <tt>ScrollableResults</tt>
 * </ul>
 * <br>
 * Use of <tt>setFirstResult()</tt> requires that the JDBC driver implement
 * scrollable result sets.<br>
 * <br>
 * Named query parameters are tokens of the form <tt>:name</tt> in the
 * query string. A value is bound to the <tt>integer</tt> parameter
 * <tt>:foo</tt> by calling<br>
 * <br>
 * <tt>setParameter("foo", foo, Hibernate.INTEGER);</tt><br>
 * <br>
 * for example. A name may appear multiple times in the query string.<br>
 * <br>
 * JDBC-style <tt>?</tt> parameters are also supported. To bind a
 * value to a JDBC-style parameter use a set method that accepts an
 * <tt>int</tt> positional argument (numbered from zero, contrary
 * to JDBC).<br>
 * <br>
 * You may not mix and match JDBC-style parameters and named parameters
 * in the same query.<br>
 * <br>
 * Queries are executed by calling <tt>list()</tt>, <tt>scroll()</tt> or 
 * <tt>iterate()</tt>. A query may be re-executed by subsequent invocations. 
 * Its lifespan is, however, bounded by the lifespan of the <tt>Session</tt> 
 * that created it.<br>
 * <br>
 * Implementors are not intended to be threadsafe.
 *
 * @see Session#createQuery(java.lang.String)
 * @see ScrollableResults
 * @author Gavin King
 */
public interface Query {
	/**
	 * Get the query string.
	 *
	 * @return the query string
	 */
	public String getQueryString();
	/**
	 * Return the Hibernate types of the query result set.
	 * @return an array of types
	 */
	public Type[] getReturnTypes() throws HibernateException;
	/**
	 * Return the names of all named parameters of the query.
	 * @return the parameter names, in no particular order
	 */
	public String[] getNamedParameters() throws HibernateException;
	/**
	 * Return the query results as an <tt>Iterator</tt>. If the query
	 * contains multiple results pre row, the results are returned in
	 * an instance of <tt>Object[]</tt>.<br>
	 * <br>
	 * Entities returned as results are initialized on demand. The first
	 * SQL query returns identifiers only.<br>
	 *
	 * @return the result iterator
	 * @throws HibernateException
	 */
	public Iterator iterate() throws HibernateException;
	/**
	 * Return the query results as <tt>ScrollableResults</tt>. The
	 * scrollability of the returned results depends upon JDBC driver
	 * support for scrollable <tt>ResultSet</tt>s.<br>
	 * <br>
	 * Entities returned as results are initialized on demand. The first
	 * SQL query returns identifier only.<br>
	 *
	 * @see ScrollableResults
	 * @return the result iterator
	 * @throws HibernateException
	 */
	public ScrollableResults scroll() throws HibernateException;
	/**
	 * Return the query results as a <tt>List</tt>. If the query contains
	 * multiple results pre row, the results are returned in an instance
	 * of <tt>Object[]</tt>.
	 *
	 * @return the result list
	 * @throws HibernateException
	 */
	public List list() 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;
	
	/**
	 * Set the maximum number of rows to retrieve. If not set,
	 * there is no limit to the number of rows retrieved.
	 * @param maxResults the maximum number of rows
	 */
	public Query setMaxResults(int maxResults);
	/**
	 * Set the first row to retrieve. If not set, rows will be
	 * retrieved beginnning from row <tt>0</tt>.
	 * @param firstResult a row number, numbered from <tt>0</tt>
	 */
	public Query setFirstResult(int firstResult);
	
	/**
	 * Enable caching of this query result set.
	 * @param cacheable Should the query results be cacheable?
	 */
	public Query setCacheable(boolean cacheable);

	/**
	 * Set the name of the cache region.
	 * @param cacheRegion the name of a query cache region, or <tt>null</tt>
	 * for the default query cache
	 */
	public Query setCacheRegion(String cacheRegion);

	/**
	 * Should the query force a refresh of the specified query cache region?
	 * This is particularly useful in cases where underlying data may have been
	 * updated via a seperate process (i.e., not modified through Hibernate) and
	 * allows the application to selectively refresh the query cache regions
	 * based on its knowledge of those events.
	 * @param forceCacheRefresh Should the query result in a forceable refresh of
	 * the query cache?
	 */
	public Query setForceCacheRefresh(boolean forceCacheRefresh);

	/**
	 * Set a timeout for the underlying JDBC query.
	 * @param timeout the timeout in seconds
	 */
	public Query setTimeout(int timeout);
	/**
	 * Set a fetch size for the underlying JDBC query.
	 * @param fetchSize the fetch size
	 */
	public Query setFetchSize(int fetchSize);
	
	/**
	 * Set the lockmode for the objects idententified by the
	 * given alias that appears in the <tt>FROM</tt> clause.
	 * @param alias a query alias, or <tt>this</tt> for a collection filter
	 */
	public void setLockMode(String alias, LockMode lockMode);
	
	/**
	 * Bind a value to a JDBC-style query parameter.
	 * @param position the position of the parameter in the query
	 * string, numbered from <tt>0</tt>.
	 * @param val the possibly-null parameter value
	 * @param type the Hibernate type
	 */
	public Query setParameter(int position, Object val, Type type);
	/**
	 * Bind a value to a named query parameter.
	 * @param name the name of the parameter
	 * @param val the possibly-null parameter value
	 * @param type the Hibernate type
	 */
	public Query setParameter(String name, Object val, Type type);
	
	/**
	 * Bind a value to a JDBC-style query parameter, guessing the
	 * Hibernate type from the class of the given object.
	 * @param position the position of the parameter in the query
	 * string, numbered from <tt>0</tt>.
	 * @param val the non-null parameter value
	 * @throws net.sf.hibernate.HibernateException if no type could be determined
	 */
	public Query setParameter(int position, Object val) throws HibernateException;
	/**
	 * Bind a value to a named query parameter, guessing the Hibernate
	 * type from the class of the given object.
	 * @param name the name of the parameter
	 * @param val the non-null parameter value
	 * @throws net.sf.hibernate.HibernateException if no type could be determined
	 */
	public Query setParameter(String name, Object val) throws HibernateException;
	
	/**
	 * Bind multiple values to a named query parameter. This is useful for binding
	 * a list of values to an expression such as <tt>foo.bar in (:value_list)</tt>.
	 * @param name the name of the parameter
	 * @param vals a collection of values to list
	 * @param type the Hibernate type of the values
	 */
	public Query setParameterList(String name, Collection vals, Type type) throws HibernateException;
	
	/**
	 * Bind multiple values to a named query parameter, guessing the Hibernate type from the
	 * class of the first object in the collection. This is useful for binding a list of values
	 * to an expression such as <tt>foo.bar in (:value_list)</tt>.
	 * @param name the name of the parameter
	 * @param vals a collection of values to list
	 */
	public Query setParameterList(String name, Collection vals) throws HibernateException;
	
	/**
	 * Bind multiple values to a named query parameter. This is useful for binding
	 * a list of values to an expression such as <tt>foo.bar in (:value_list)</tt>.
	 * @param name the name of the parameter
	 * @param vals a collection of values to list
	 * @param type the Hibernate type of the values
	 */
	public Query setParameterList(String name, Object[] vals, Type type) throws HibernateException;
	
	/**
	 * Bind multiple values to a named query parameter, guessing the Hibernate type from the
	 * class of the first object in the array. This is useful for binding a list of values
	 * to an expression such as <tt>foo.bar in (:value_list)</tt>.
	 * @param name the name of the parameter
	 * @param vals a collection of values to list
	 */
	public Query setParameterList(String name, Object[] vals) throws HibernateException;
	
	/**
	 * Bind the property values of the given bean to named parameters of the query,
	 * matching property names with parameter names and mapping property types to
	 * Hibernate types using hueristics.
	 * @param bean any JavaBean or POJO
	 */
	public Query setProperties(Object bean) throws HibernateException;
	
	public Query setString(int position, String val);
	public Query setCharacter(int position, char val);
	public Query setBoolean(int position, boolean val);
	public Query setByte(int position, byte val);
	public Query setShort(int position, short val);
	public Query setInteger(int position, int val);
	public Query setLong(int position, long val);
	public Query setFloat(int position, float val);
	public Query setDouble(int position, double val);
	public Query setBinary(int position, byte[] val);
	public Query setText(int position, String val);
	public Query setSerializable(int position, Serializable val);
	public Query setLocale(int position, Locale locale);
	public Query setBigDecimal(int position, BigDecimal number);
	
	public Query setDate(int position, Date date);
	public Query setTime(int position, Date date);
	public Query setTimestamp(int position, Date date);
	
	public Query setCalendar(int position, Calendar calendar);
	public Query setCalendarDate(int position, Calendar calendar);
	
	public Query setString(String name, String val);
	public Query setCharacter(String name, char val);
	public Query setBoolean(String name, boolean val);
	public Query setByte(String name, byte val);
	public Query setShort(String name, short val);
	public Query setInteger(String name, int val);
	public Query setLong(String name, long val);
	public Query setFloat(String name, float val);
	public Query setDouble(String name, double val);
	public Query setBinary(String name, byte[] val);
	public Query setText(String name, String val);
	public Query setSerializable(String name, Serializable val);
	public Query setLocale(String name, Locale locale);
	public Query setBigDecimal(String name, BigDecimal number);
	
	public Query setDate(String name, Date date);
	public Query setTime(String name, Date date);
	public Query setTimestamp(String name, Date date);
	
	public Query setCalendar(String name, Calendar calendar);
	public Query setCalendarDate(String name, Calendar calendar);
	
	/**
	 * Bind an instance of a mapped persistent class to a JDBC-style query parameter.
	 * @param position the position of the parameter in the query
	 * string, numbered from <tt>0</tt>.
	 * @param val a non-null instance of a persistent class
	 */
	public Query setEntity(int position, Object val); // use setParameter for null values
	/**
	 * Bind an instance of a persistent enumeration class to a JDBC-style query parameter.
	 * @param position the position of the parameter in the query
	 * string, numbered from <tt>0</tt>.
	 * @param val a non-null instance of a persistent enumeration
     * @deprecated Support for PersistentEnums will be removed in 2.2
	 */
	public Query setEnum(int position, Object val) throws MappingException; // use setParameter for null values
	
	/**
	 * Bind an instance of a mapped persistent class to a named query parameter.
	 * @param name the name of the parameter
	 * @param val a non-null instance of a persistent class
	 */
	public Query setEntity(String name, Object val); // use setParameter for null values
	/**
	 * Bind an instance of a mapped persistent enumeration class to a named query parameter.
	 * @param name the name of the parameter
	 * @param val a non-null instance of a persistent enumeration
     * @deprecated Support for PersistentEnums will be removed in 2.2
	 */
	public Query setEnum(String name, Object val) throws MappingException; // use setParameter for null values
}







