org.hibernate.dialect.ColumnAliasExtractor Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2011, 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;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
/**
* Strategy for extracting the unique column alias out of a {@link ResultSetMetaData}. This is used during the
* "auto discovery" phase of native SQL queries.
*
* Generally this should be done via {@link ResultSetMetaData#getColumnLabel}, but not all drivers do this correctly.
*
* @author Steve Ebersole
*/
public interface ColumnAliasExtractor {
/**
* Extract the unique column alias.
*
* @param metaData The result set metadata
* @param position The column position
*
* @return The alias
*
* @throws SQLException Indicates a problem accessing the JDBC ResultSetMetaData
*/
public String extractColumnAlias(ResultSetMetaData metaData, int position) throws SQLException;
/**
* An extractor which uses {@link ResultSetMetaData#getColumnLabel}
*/
public static final ColumnAliasExtractor COLUMN_LABEL_EXTRACTOR = new ColumnAliasExtractor() {
@Override
public String extractColumnAlias(ResultSetMetaData metaData, int position) throws SQLException {
return metaData.getColumnLabel( position );
}
};
/**
* An extractor which uses {@link ResultSetMetaData#getColumnName}
*/
@SuppressWarnings("UnusedDeclaration")
public static final ColumnAliasExtractor COLUMN_NAME_EXTRACTOR = new ColumnAliasExtractor() {
@Override
public String extractColumnAlias(ResultSetMetaData metaData, int position) throws SQLException {
return metaData.getColumnName( position );
}
};
}