rowcountprojection.java

hibernate-3.1.3-all-src.zip 面向对象的访问数据库工具

//$Id: RowCountProjection.java 5685 2005-02-12 07:19:50Z steveebersole $
package org.hibernate.criterion;

import org.hibernate.Criteria;
import org.hibernate.Hibernate;
import org.hibernate.HibernateException;
import org.hibernate.type.Type;

/**
 * A row count
 * @author Gavin King
 */
public class RowCountProjection extends SimpleProjection {

	protected RowCountProjection() {}

	public String toString() {
		return "count(*)";
	}

	public Type[] getTypes(Criteria criteria, CriteriaQuery criteriaQuery) 
	throws HibernateException {
		return new Type[] { Hibernate.INTEGER };
	}

	public String toSqlString(Criteria criteria, int position, CriteriaQuery criteriaQuery) 
	throws HibernateException {
		return new StringBuffer()
			.append("count(*) as y")
			.append(position)
			.append('_')
			.toString();
	}

}