jdbcresultset.java

纯Java的数据库

     * The value can then be read in chunks from the
     * stream. This method is particularly
     * suitable for retrieving large <code>LONGVARCHAR</code>values.  The
     * JDBC driver will do any necessary conversion from the database
     * format into Unicode.
     *
     * <P><B>Note:</B> All the data in the returned stream must be
     * read prior to getting the value of any other column. The next
     * call to a getter method implicitly closes the stream.
     * Also, a stream may return <code>0</code> when the method
     * <code>InputStream.available</code>
     * is called, whether there is data available or not. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * The limitation noted above does not apply to HSQLDB.<p>
     *
     * Up to and including 1.6.1, getUnicodeStream (and getAsciiStream)
     * both simply returned a byte stream constructed from the
     * raw {@link #getBytes(int) getBytes} representation.
     *
     * Starting with 1.7.0, this has been corrected to comply with the
     * java.sql specification.
     *
     * When the column is of type CHAR and its variations, it requires no
     * conversion since it is represented internally already as
     * Java Strings. When the column is not of type CHAR and its variations,
     * the returned stream is based on a conversion to the
     * Java <code>String</code> representation of the value. In either case,
     * the obtained stream is always equivalent to a stream of
     * bytes from the value's String representation, with high-byte first.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return a Java input stream that delivers the database column value
     *   as a stream of two-byte Unicode characters;
     *   if the value is SQL <code>NULL</code>, the value returned is
     *   <code>null</code>
     * @exception SQLException if a database access error occurs
     * @deprecated use <code>getCharacterStream</code> in place of
     *        <code>getUnicodeStream</code>
     */

//#ifdef DEPRECATEDJDBC
    public java.io.InputStream getUnicodeStream(int columnIndex)
    throws SQLException {

        String s = getString(columnIndex);

        if (s == null) {
            return null;
        }

        return new StringInputStream(s);
    }

//#endif

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as a binary stream of
     * uninterpreted bytes. The value can then be read in chunks from the
     * stream. This method is particularly
     * suitable for retrieving large <code>LONGVARBINARY</code> values.
     *
     * <P><B>Note:</B> All the data in the returned stream must be
     * read prior to getting the value of any other column. The next
     * call to a getter method implicitly closes the stream.  Also, a
     * stream may return <code>0</code> when the method
     * <code>InputStream.available</code>
     * is called whether there is data available or not. <p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return a Java input stream that delivers the database column value
     *     as a stream of uninterpreted bytes;
     *     if the value is SQL <code>NULL</code>, the value returned is
     *     <code>null</code>
     * @exception SQLException if a database access error occurs
     */
// fredt@users 20020215 - patch 485704 by boucherb@users
    public java.io.InputStream getBinaryStream(int columnIndex)
    throws SQLException {

        byte[] b = getBytes(columnIndex);

        return wasNull() ? null
                         : new ByteArrayInputStream(b);
    }

    //======================================================================
    // Methods for accessing results by column name
    //======================================================================

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>String</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public String getString(String columnName) throws SQLException {
        return getString(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>boolean</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>false</code>
     * @exception SQLException if a database access error occurs
     */
    public boolean getBoolean(String columnName) throws SQLException {
        return getBoolean(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>byte</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public byte getByte(String columnName) throws SQLException {
        return getByte(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>short</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public short getShort(String columnName) throws SQLException {
        return getShort(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * an <code>int</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public int getInt(String columnName) throws SQLException {
        return getInt(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>long</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public long getLong(String columnName) throws SQLException {
        return getLong(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>float</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public float getFloat(String columnName) throws SQLException {
        return getFloat(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>double</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public double getDouble(String columnName) throws SQLException {
        return getDouble(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as a
     * <code>java.math.BigDecimal</code> in the Java programming language.<p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Beginning with 1.7.0, HSQLDB converts the result and sets the scale
     * with BigDecimal.ROUND_HALF_DOWN.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @param columnName the SQL name of the column
     * @param scale the number of digits to the right of the decimal point
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     * @deprecated by java.sun.com as of JDK 1.2
     */

//#ifdef DEPRECATEDJDBC
    public BigDecimal getBigDecimal(String columnName,
                                    int scale) throws SQLException {
        return getBigDecimal(findColumn(columnName), scale);
    }

//#endif

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>byte</code> array in the Java programming language.
     * The bytes represent the raw values returned by the driver. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public byte[] getBytes(String columnName) throws SQLException {
        return getBytes(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as a
     * <code>java.sql.Date</code> object in the Java programming language.<p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public Date getDate(String columnName) throws SQLException {
        return getDate(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as a <code>java.sql.Time</code>
     * object in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnName the SQL name of the column
     * @return the column value;
     * if the value is SQL <code>NULL</code>,
     * the value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public Time getTime(String columnName) throws SQLException {
        return getTime(findColumn(columnName));
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>java.sql.Timestamp</code> object. <p>
     * <!-- end generic documentation -->