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JDBC Type 4 driver for MySQL
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/*
 * Copyright (c) 2015, 2020, Oracle and/or its affiliates.
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, version 2.0, as published by the
 * Free Software Foundation.
 *
 * This program is also distributed with certain software (including but not
 * limited to OpenSSL) that is licensed under separate terms, as designated in a
 * particular file or component or in included license documentation. The
 * authors of MySQL hereby grant you an additional permission to link the
 * program and your derivative works with the separately licensed software that
 * they have included with MySQL.
 *
 * Without limiting anything contained in the foregoing, this file, which is
 * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
 * version 1.0, a copy of which can be found at
 * http://oss.oracle.com/licenses/universal-foss-exception.
 *
 * 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 General Public License, version 2.0,
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
 */

package com.mysql.cj.result;

import com.mysql.cj.Messages;
import com.mysql.cj.exceptions.CJOperationNotSupportedException;
import com.mysql.cj.exceptions.ExceptionFactory;
import com.mysql.cj.protocol.ColumnDefinition;
import com.mysql.cj.protocol.ProtocolEntity;
import com.mysql.cj.protocol.ValueDecoder;

public interface Row extends ProtocolEntity {
    /**
     * Retrieve a value for the given column. This is the main facility to access values from the Row
     * involving {@link ValueDecoder} and {@link ValueFactory} chain. Metadata must be set via
     * Row constructor or {@link #setMetadata(ColumnDefinition)} call before calling this method to allow
     * correct columnIndex boundaries check and data type recognition.
     *
     * @param 
     *            type to decode to
     * @param columnIndex
     *            index of column to retrieve value from (0-indexed, not JDBC 1-indexed)
     * @param vf
     *            value factory used to create the return value after decoding
     * @return The return value from the value factory
     */
     T getValue(int columnIndex, ValueFactory vf);

    /**
     * Set metadata to enable getValue functionality.
     * 
     * @param columnDefinition
     *            {@link ColumnDefinition}
     * @return {@link Row}
     */
    default Row setMetadata(ColumnDefinition columnDefinition) {
        throw ExceptionFactory.createException(CJOperationNotSupportedException.class, Messages.getString("OperationNotSupportedException.0"));
    }

    /**
     * Returns the value at the given column as a byte array.
     * The bytes represent the raw values returned by the server.
     * 
     * @param columnIndex
     *            index of column (starting at 0) to return from.
     * @return the value for the given column; if the value is SQL NULL, the value returned is null
     */
    default byte[] getBytes(int columnIndex) {
        // TODO check that "if the value is SQL NULL, the value returned is null" is correctly implemented
        throw ExceptionFactory.createException(CJOperationNotSupportedException.class, Messages.getString("OperationNotSupportedException.0"));
    }

    /**
     * Sets the given byte array as a raw column value (only works currently with ByteArrayRow).
     * 
     * @param columnIndex
     *            index of the column (starting at 0) to set to.
     * @param value
     *            the (raw) value to set
     */
    default void setBytes(int columnIndex, byte[] value) {
        throw ExceptionFactory.createException(CJOperationNotSupportedException.class, Messages.getString("OperationNotSupportedException.0"));
    }

    /**
     * Check whether a column is NULL and update the 'wasNull' status.
     * 
     * @param columnIndex
     *            of the column value (starting at 0) to check.
     * 
     * @return true if the column value is NULL, false if not.
     */
    boolean getNull(int columnIndex);

    /**
     * Was the last value retrieved a NULL value?
     * 
     * @return true if the last retrieved value was NULL.
     */
    boolean wasNull();
}