org.hibernate.dialect.function.SQLFunction Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.dialect.function;
import java.util.List;
import org.hibernate.QueryException;
import org.hibernate.engine.spi.Mapping;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.type.Type;
/**
* Provides support routines for the HQL functions as used
* in the various SQL Dialects
*
* Provides an interface for supporting various HQL functions that are
* translated to SQL. The Dialect and its sub-classes use this interface to
* provide details required for processing of the function.
*
* @author David Channon
* @author Steve Ebersole
*/
public interface SQLFunction {
/**
* Does this function have any arguments?
*
* @return True if the function expects to have parameters; false otherwise.
*/
public boolean hasArguments();
/**
* If there are no arguments, are parentheses required?
*
* @return True if a no-arg call of this function requires parentheses.
*/
public boolean hasParenthesesIfNoArguments();
/**
* The return type of the function. May be either a concrete type which is preset, or variable depending upon
* the type of the first function argument.
*
* Note, the 'firstArgumentType' parameter should match the one passed into {@link #render}
*
* @param firstArgumentType The type of the first argument
* @param mapping The mapping source.
*
* @return The type to be expected as a return.
*
* @throws org.hibernate.QueryException Indicates an issue resolving the return type.
*/
public Type getReturnType(Type firstArgumentType, Mapping mapping) throws QueryException;
/**
* Render the function call as SQL fragment.
*
* Note, the 'firstArgumentType' parameter should match the one passed into {@link #getReturnType}
*
* @param firstArgumentType The type of the first argument
* @param arguments The function arguments
* @param factory The SessionFactory
*
* @return The rendered function call
*
* @throws org.hibernate.QueryException Indicates a problem rendering the
* function call.
*/
public String render(Type firstArgumentType, List arguments, SessionFactoryImplementor factory) throws QueryException;
}