com.codename1.db.Cursor Maven / Gradle / Ivy
/*
* Copyright (c) 2012, Codename One and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Codename One designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Codename One through http://www.codenameone.com/ if you
* need additional information or have any questions.
*/
package com.codename1.db;
import java.io.IOException;
/**
* The Cursor interface is used to iterate over the results returned from a database query.
* IMPORTANT: Notice that some methods might not be supported on all platforms!
*
* There is more thorough coverage of the {@link com.codename1.db Database API here}.
* The sample code below presents a Database Explorer tool that allows executing arbitrary SQL and
* viewing the tabular results:
*
* 
* 
*
* @author Chen
*/
public interface Cursor {
/**
* Move the cursor to the first row.
*
* If cursor provides forward-only navigation and is positioned after the
* first row then calling first() method would throw a IOException.
* @return true if succeeded
* @throws IOException
*/
public boolean first() throws IOException;
/**
* Move the cursor to the last row.
*
* @return true if succeeded
* @throws IOException
*/
public boolean last() throws IOException;
/**
* Moves the cursor to the next row.
* Calling next() method the first time will position cursor on the first.
*
* @return true if succeeded
* @throws IOException
*/
public boolean next() throws IOException;
/**
* Moves the cursor to the previous row.
* If cursor is forward type then calling prev() would throw a IOException.
*
* @return true if succeeded
* @throws IOException
*/
public boolean prev() throws IOException;
/**
* Returns the zero-based index for a given column name.
* Note that columns meta information is available only after navigation to
* the first row
*
* @param columnName the name of the column.
* @return the index of the column
* @throws IOException
*/
public int getColumnIndex(String columnName) throws IOException;
/**
* Returns the column name at a given zero-based column index.
* Note that columns meta information is available only after navigation to
* the first row
*
* @param columnIndex the index of the column
* @return the name of the column
*
* @throws IOException
*/
public String getColumnName(int columnIndex) throws IOException;
/**
* Returns the column count
* @return the column count
* @throws IOException
*/
public int getColumnCount() throws IOException;
/**
* Returns the current Cursor position.
*
* @return the cursor position
* @throws IOException
*/
public int getPosition() throws IOException;
/**
* Move the cursor to an absolute row position
*
* @param row position to move to
* @return true if succeeded
* @throws IOException
*/
public boolean position(int row) throws IOException;
/**
* Close the cursor and release its resources
* @throws IOException
*/
public void close() throws IOException;
/**
* Get the Row data Object.
*
* @return a Row Object
* @throws IOException
*/
public Row getRow() throws IOException;
}