--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/sql/rowset/Joinable.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,291 @@
+/*
+ * Copyright 2003-2004 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.sql.rowset;
+
+import java.sql.SQLException;
+
+/**
+ * <h3>1.0 Background</h3>
+ * The <code>Joinable</code> interface provides the methods for getting and
+ * setting a match column, which is the basis for forming the SQL <code>JOIN</code>
+ * formed by adding <code>RowSet</code> objects to a <code>JoinRowSet</code>
+ * object.
+ * <P>
+ * Any standard <code>RowSet</code> implementation <b>may</b> implement
+ * the <code>Joinable</code> interface in order to be
+ * added to a <code>JoinRowSet</code> object. Implementing this interface gives
+ * a <code>RowSet</code> object the ability to use <code>Joinable</code> methods,
+ * which set, retrieve, and get information about match columns. An
+ * application may add a
+ * <code>RowSet</code> object that has not implemented the <code>Joinable</code>
+ * interface to a <code>JoinRowSet</code> object, but to do so it must use one
+ * of the <code>JoinRowSet.addRowSet</code> methods that takes both a
+ * <code>RowSet</code> object and a match column or an array of <code>RowSet</code>
+ * objects and an array of match columns.
+ * <P>
+ * To get access to the methods in the <code>Joinable</code> interface, a
+ * <code>RowSet</code> object implements at least one of the
+ * five standard <code>RowSet</code> interfaces and also implements the
+ * <code>Joinable</code> interface. In addition, most <code>RowSet</code>
+ * objects extend the <code>BaseRowSet</code> class. For example:
+ * <pre>
+ * class MyRowSetImpl extends BaseRowSet implements CachedRowSet, Joinable {
+ * :
+ * :
+ * }
+ * </pre>
+ * <P>
+ * <h3>2.0 Usage Guidelines</h3>
+ * <P>
+ * The methods in the <code>Joinable</code> interface allow a <code>RowSet</code> object
+ * to set a match column, retrieve a match column, or unset a match column, which is
+ * the column upon which an SQL <code>JOIN</code> can be based.
+ * An instance of a class that implements these methods can be added to a
+ * <code>JoinRowSet</code> object to allow an SQL <code>JOIN</code> relationship to
+ * be established.
+ * <p>
+ * <pre>
+ * CachedRowSet crs = new MyRowSetImpl();
+ * crs.populate((ResultSet)rs);
+ * (Joinable)crs.setMatchColumnIndex(1);
+ *
+ * JoinRowSet jrs = new JoinRowSetImpl();
+ * jrs.addRowSet(crs);
+ * </pre>
+ * In the previous example, <i>crs</i> is a <code>CachedRowSet</code> object that
+ * has emplemented the <code>Joinable</code> interface. In the following example,
+ * <i>crs2</i> has not, so it must supply the match column as an argument to the
+ * <code>addRowSet</code> method. This example assumes that column 1 is the match
+ * column.
+ * <PRE>
+ * CachedRowSet crs2 = new MyRowSetImpl();
+ * crs2.populate((ResultSet)rs);
+ *
+ * JoinRowSet jrs2 = new JoinRowSetImpl();
+ * jrs2.addRowSet(crs2, 1);
+ * </PRE>
+ * <p>
+ * The <code>JoinRowSet</code> interface makes it possible to get data from one or
+ * more <code>RowSet</code> objects consolidated into one table without having to incur
+ * the expense of creating a connection to a database. It is therefore ideally suited
+ * for use by disconnected <code>RowSet</code> objects. Nevertheless, any
+ * <code>RowSet</code> object <b>may</b> implement this interface
+ * regardless of whether it is connected or disconnected. Note that a
+ * <code>JdbcRowSet</code> object, being always connected to its data source, can
+ * become part of an SQL <code>JOIN</code> directly without having to become part
+ * of a <code>JoinRowSet</code> object.
+ * <P>
+ * <h3>3.0 Managing Multiple Match Columns</h3>
+ * The index array passed into the <code>setMatchColumn</code> methods indicates
+ * how many match columns are being set (the length of the array) in addition to
+ * which columns will be used for the match. For example:
+ * <pre>
+ * int[] i = {1, 2, 4, 7}; // indicates four match columns, with column
+ * // indexes 1, 2, 4, 7 participating in the JOIN.
+ * Joinable.setMatchColumn(i);
+ * </pre>
+ * Subsequent match columns may be added as follows to a different <code>Joinable</code>
+ * object (a <code>RowSet</code> object that has implemented the <code>Joinable</code>
+ * interface).
+ * <pre>
+ * int[] w = {3, 2, 5, 3};
+ * Joinable2.setMatchColumn(w);
+ * </pre>
+ * When an application adds two or more <code>RowSet</code> objects to a
+ * <code>JoinRowSet</code> object, the order of the indexes in the array is
+ * particularly important. Each index of
+ * the array maps directly to the corresponding index of the previously added
+ * <code>RowSet</code> object. If overlap or underlap occurs, the match column
+ * data is maintained in the event an additional <code>Joinable</code> RowSet is
+ * added and needs to relate to the match column data. Therefore, applications
+ * can set multiple match columns in any order, but
+ * this order has a direct effect on the outcome of the <code>SQL</code> JOIN.
+ * <p>
+ * This assertion applies in exactly the same manner when column names are used
+ * rather than column indexes to indicate match columns.
+ *
+ * @see JoinRowSet
+ * @author Jonathan Bruce
+ */
+public interface Joinable {
+
+ /**
+ * Sets the designated column as the match column for this <code>RowSet</code>
+ * object. A <code>JoinRowSet</code> object can now add this <code>RowSet</code>
+ * object based on the match column.
+ * <p>
+ * Sub-interfaces such as the <code>CachedRowSet</code><sup><font size=-2>TM</font></sup>
+ * interface define the method <code>CachedRowSet.setKeyColumns</code>, which allows
+ * primary key semantics to be enforced on specific columns.
+ * Implementations of the <code>setMatchColumn(int columnIdx)</code> method
+ * should ensure that the constraints on the key columns are maintained when
+ * a <code>CachedRowSet</code> object sets a primary key column as a match column.
+ *
+ * @param columnIdx an <code>int</code> identifying the index of the column to be
+ * set as the match column
+ * @throws SQLException if an invalid column index is set
+ * @see #setMatchColumn(int[])
+ * @see #unsetMatchColumn(int)
+ *
+ */
+ public void setMatchColumn(int columnIdx) throws SQLException;
+
+ /**
+ * Sets the designated columns as the match column for this <code>RowSet</code>
+ * object. A <code>JoinRowSet</code> object can now add this <code>RowSet</code>
+ * object based on the match column.
+ *
+ * @param columnIdxes an array of <code>int</code> identifying the indexes of the
+ * columns to be set as the match columns
+ * @throws SQLException if an invalid column index is set
+ * @see #setMatchColumn(int[])
+ * @see #unsetMatchColumn(int[])
+ */
+ public void setMatchColumn(int[] columnIdxes) throws SQLException;
+
+ /**
+ * Sets the designated column as the match column for this <code>RowSet</code>
+ * object. A <code>JoinRowSet</code> object can now add this <code>RowSet</code>
+ * object based on the match column.
+ * <p>
+ * Subinterfaces such as the <code>CachedRowSet</code> interface define
+ * the method <code>CachedRowSet.setKeyColumns</code>, which allows
+ * primary key semantics to be enforced on specific columns.
+ * Implementations of the <code>setMatchColumn(String columnIdx)</code> method
+ * should ensure that the constraints on the key columns are maintained when
+ * a <code>CachedRowSet</code> object sets a primary key column as a match column.
+ *
+ * @param columnName a <code>String</code> object giving the name of the column
+ * to be set as the match column
+ * @throws SQLException if an invalid column name is set, the column name
+ * is a null, or the column name is an empty string
+ * @see #unsetMatchColumn
+ * @see #setMatchColumn(int[])
+ */
+ public void setMatchColumn(String columnName) throws SQLException;
+
+ /**
+ * Sets the designated columns as the match column for this <code>RowSet</code>
+ * object. A <code>JoinRowSet</code> object can now add this <code>RowSet</code>
+ * object based on the match column.
+ *
+ * @param columnNames an array of <code>String</code> objects giving the names
+ * of the column to be set as the match columns
+ * @throws SQLException if an invalid column name is set, the column name
+ * is a null, or the column name is an empty string
+ * @see #unsetMatchColumn
+ * @see #setMatchColumn(int[])
+ */
+ public void setMatchColumn(String[] columnNames) throws SQLException;
+
+ /**
+ * Retrieves the indexes of the match columns that were set for this
+ * <code>RowSet</code> object with the method
+ * <code>setMatchColumn(int[] columnIdxes)</code>.
+ *
+ * @return an <code>int</code> array identifying the indexes of the columns
+ * that were set as the match columns for this <code>RowSet</code> object
+ * @throws SQLException if no match column has been set
+ * @see #setMatchColumn
+ * @see #unsetMatchColumn
+ */
+ public int[] getMatchColumnIndexes() throws SQLException;
+
+ /**
+ * Retrieves the names of the match columns that were set for this
+ * <code>RowSet</code> object with the method
+ * <code>setMatchColumn(String [] columnNames)</code>.
+ *
+ * @return an array of <code>String</code> objects giving the names of the columns
+ * set as the match columns for this <code>RowSet</code> object
+ * @throws SQLException if no match column has been set
+ * @see #setMatchColumn
+ * @see #unsetMatchColumn
+ *
+ */
+ public String[] getMatchColumnNames() throws SQLException;
+
+ /**
+ * Unsets the designated column as the match column for this <code>RowSet</code>
+ * object.
+ * <P>
+ * <code>RowSet</code> objects that implement the <code>Joinable</code> interface
+ * must ensure that a key-like constraint continues to be enforced until the
+ * method <code>CachedRowSet.unsetKeyColumns</code> has been called on the
+ * designated column.
+ *
+ * @param columnIdx an <code>int</code> that identifies the index of the column
+ * that is to be unset as a match column
+ * @throws SQLException if an invalid column index is designated or if
+ * the designated column was not previously set as a match
+ * column
+ * @see #setMatchColumn
+ */
+ public void unsetMatchColumn(int columnIdx) throws SQLException;
+
+ /**
+ * Unsets the designated columns as the match column for this <code>RowSet</code>
+ * object.
+ *
+ * @param columnIdxes an arrary of <code>int</code> that identifies the indexes
+ * of the columns that are to be unset as match columns
+ * @throws SQLException if an invalid column index is designated or if
+ * the designated column was not previously set as a match
+ * column
+ * @see #setMatchColumn
+ */
+ public void unsetMatchColumn(int[] columnIdxes) throws SQLException;
+
+ /**
+ * Unsets the designated column as the match column for this <code>RowSet</code>
+ * object.
+ * <P>
+ * <code>RowSet</code> objects that implement the <code>Joinable</code> interface
+ * must ensure that a key-like constraint continues to be enforced until the
+ * method <code>CachedRowSet.unsetKeyColumns</code> has been called on the
+ * designated column.
+ *
+ * @param columnName a <code>String</code> object giving the name of the column
+ * that is to be unset as a match column
+ * @throws SQLException if an invalid column name is designated or
+ * the designated column was not previously set as a match
+ * column
+ * @see #setMatchColumn
+ */
+ public void unsetMatchColumn(String columnName) throws SQLException;
+
+ /**
+ * Unsets the designated columns as the match columns for this <code>RowSet</code>
+ * object.
+ *
+ * @param columnName an array of <code>String</code> objects giving the names of
+ * the columns that are to be unset as the match columns
+ * @throws SQLException if an invalid column name is designated or the
+ * designated column was not previously set as a match column
+ * @see #setMatchColumn
+ */
+ public void unsetMatchColumn(String[] columnName) throws SQLException;
+}