jdbcstatement.java

hsqldb是100％java实现的数据库,是一个开放源代码的JAVA数据库 l 具有标准的SQL语法和JAVA接口 l HSQLDB可以自由使用和分发 l 非常简洁和快速的

     * Retrieves the current result as a <code>ResultSet</code> object.
     * This method should be called only once per result. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Without an interceding call to executeXXX, each invocation of this
     * method will produce a new, initialized ResultSet instance referring to
     * the current result, if any.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @return the current result as a <code>ResultSet</code> object or
     *      <code>null</code> if the result is an update count or there
     *      are no more results
     * @exception SQLException if a database access error occurs
     * @see #execute
     */
    public ResultSet getResultSet() throws SQLException {

        checkClosed();

        return resultIn == null ||!resultIn.isData() ? null
                                                     : new jdbcResultSet(this,
                                                     resultIn,
                                                         connection.connProperties,
                                                             connection.isNetConn);
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the current result as an update count;
     * if the result is a <code>ResultSet</code> object or there are no more results, -1
     * is returned. This method should be called only once per result. <p>
     * <!-- end generic documentation -->
     *
     * @return the current result as an update count; -1 if the current result is a
     * <code>ResultSet</code> object or there are no more results
     * @exception SQLException if a database access error occurs
     * @see #execute
     */
    public int getUpdateCount() throws SQLException {

// fredt - omit checkClosed() in order to be able to handle the result of a
// SHUTDOWN query
//        checkClosed();
        return (resultIn == null || resultIn.isData()) ? -1
                                                       : resultIn
                                                       .getUpdateCount();
    }

    /**
     * <!-- start generic documentation -->
     * Moves to this <code>Statement</code> object's next result, returns
     * <code>true</code> if it is a <code>ResultSet</code> object, and
     * implicitly closes any current <code>ResultSet</code>
     * object(s) obtained with the method <code>getResultSet</code>.
     *
     * <P>There are no more results when the following is true:
     * <PRE>
     *    <code>(!getMoreResults() && (getUpdateCount() == -1)</code>
     * </PRE> <p>
     * <!-- end generic documentation -->
     *
     * @return <code>true</code> if the next result is a <code>ResultSet</code>
     *       object; <code>false</code> if it is an update count or there are
     *       no more results
     * @exception SQLException if a database access error occurs
     * @see #execute
     */
    public boolean getMoreResults() throws SQLException {

        checkClosed();

        resultIn = null;

        return false;
    }

    //--------------------------JDBC 2.0-----------------------------

    /**
     * <!-- start generic documentation -->
     * Gives the driver a hint as to the direction in which
     * rows will be processed in <code>ResultSet</code>
     * objects created using this <code>Statement</code> object.  The
     * default value is <code>ResultSet.FETCH_FORWARD</code>.
     * <P>
     * Note that this method sets the default fetch direction for
     * result sets generated by this <code>Statement</code> object.
     * Each result set has its own methods for getting and setting
     * its own fetch direction. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Including 1.7.2, HSQLDB supports only <code>FETCH_FORWARD</code>. <p>
     *
     * Setting any other value will throw an <code>SQLException</code>
     * stating that the operation is not supported.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @param direction the initial direction for processing rows
     * @exception SQLException if a database access error occurs
     * or the given direction
     * is not one of <code>ResultSet.FETCH_FORWARD</code>,
     * <code>ResultSet.FETCH_REVERSE</code>, or
     * <code>ResultSet.FETCH_UNKNOWN</code> <p>
     *
     * HSQLDB throws for all values except <code>FETCH_FORWARD</code>
     * @since JDK 1.2 (JDK 1.1.x developers: read the new overview
     *    for jdbcStatement)
     * @see #getFetchDirection
     */
    public void setFetchDirection(int direction) throws SQLException {

        checkClosed();

        if (direction != jdbcResultSet.FETCH_FORWARD) {
            throw Util.notSupported();
        }
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the direction for fetching rows from
     * database tables that is the default for result sets
     * generated from this <code>Statement</code> object.
     * If this <code>Statement</code> object has not set
     * a fetch direction by calling the method <code>setFetchDirection</code>,
     * the return value is implementation-specific. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Including 1.7.2, HSQLDB always returns FETCH_FORWARD.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @return the default fetch direction for result sets generated
     *        from this <code>Statement</code> object
     * @exception SQLException if a database access error occurs
     * @since JDK 1.2 (JDK 1.1.x developers: read the new overview
     *    for jdbcStatement)
     * @see #setFetchDirection
     */
    public int getFetchDirection() throws SQLException {

        checkClosed();

        return jdbcResultSet.FETCH_FORWARD;
    }

    /**
     * <!-- start generic documentation -->
     * Gives the JDBC driver a hint as to the number of rows that should
     * be fetched from the database when more rows are needed.  The number
     * of rows specified affects only result sets created using this
     * statement. If the value specified is zero, then the hint is ignored.
     * The default value is zero. <p>
     * <!-- start generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Including 1.7.2, calls to this method are ignored;
     * HSQLDB fetches each result completely as part of
     * executing its statement.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @param rows the number of rows to fetch
     * @exception SQLException if a database access error occurs, or the
     *     condition 0 <= <code>rows</code> <= <code>this.getMaxRows()</code>
     *     is not satisfied. <p>
     *
     *     HSQLDB never throws an exception, since calls to this method
     *     are always ignored.
     * @since JDK 1.2 (JDK 1.1.x developers: read the new overview
     *   for jdbcStatement)
     * @see #getFetchSize
     */
    public void setFetchSize(int rows) throws SQLException {
        checkClosed();
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the number of result set rows that is the default
     * fetch size for <code>ResultSet</code> objects
     * generated from this <code>Statement</code> object.
     * If this <code>Statement</code> object has not set
     * a fetch size by calling the method <code>setFetchSize</code>,
     * the return value is implementation-specific. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <b>HSQLDB-Specific Information</b> <p>
     *
     * Including 1.7.2, this method always returns 0.
     * HSQLDB fetches each result completely as part of
     * executing its statement
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @return the default fetch size for result sets generated
     *      from this <code>Statement</code> object
     * @exception SQLException if a database access error occurs
     * @since JDK 1.2 (JDK 1.1.x developers: read the new overview
     *  for jdbcStatement)
     * @see #setFetchSize
     */
    public int getFetchSize() throws SQLException {

        checkClosed();

        return 0;
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the result set concurrency for <code>ResultSet</code> objects
     * generated by this <code>Statement</code> object. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Including 1.7.2, HSQLDB supports only
     * <code>CONCUR_READ_ONLY</code> concurrency.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @return either <code>ResultSet.CONCUR_READ_ONLY</code> or
     * <code>ResultSet.CONCUR_UPDATABLE</code> (not supported)
     * @exception SQLException if a database access error occurs
     * @since JDK 1.2 (JDK 1.1.x developers: read the new overview
     *  for jdbcStatement)
     */
    public int getResultSetConcurrency() throws SQLException {

        checkClosed();

        return jdbcResultSet.CONCUR_READ_ONLY;
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the result set type for <code>ResultSet</code> objects
     * generated by this <code>Statement</code> object. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB 1.7.0 and later versions support <code>TYPE_FORWARD_ONLY</code>
     * and <code>TYPE_SCROLL_INSENSITIVE</code>.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @return one of <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     * <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
     * <code>ResultSet.TYPE_SCROLL_SENSITIVE</code> (not supported) <p>
     *
     * <b>Note:</b> Up to and including 1.7.1, HSQLDB never returns
     * <code>TYPE_SCROLL_SENSITIVE</code>
     * @exception SQLException if a database access error occurs
     * @since JDK 1.2 (JDK 1.1.x developers: read the new overview
     *   for jdbcStatement)
     */
    public int getResultSetType() throws SQLException {

// fredt - omit checkClosed() in order to be able to handle the result of a
// SHUTDOWN query
//        checkClosed();
        return rsType;
    }

    /**
     * <!-- start generic documentation -->
     * Adds the given SQL command to the current list of commmands for this
     * <code>Statement</code> object. The commands in this list can be
     * executed as a batch by calling the method <code>executeBatch</code>.
     * <P>
     * <B>NOTE:</B>  This method is optional. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Starting with 1.7.2, this feature is supported.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @param sql typically this is a static SQL <code>INSERT</code> or
     * <code>UPDATE</code> statement
     * @exception SQLException if a database access error occurs, or the
     * driver does not support batch updates
     * @see #executeBatch
     * @since JDK 1.2 (JDK 1.1.x developers: read the new overview
     *   for jdbcStatement)
     */
    public void addBatch(String sql) throws SQLException {

        checkClosed();