| /* |
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| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
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| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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| * accompanied this code). |
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| |
| 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> |
| * |
| * <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. |
| * |
| * <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 implemented 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. |
| * |
| * <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 |
| * @since 1.5 |
| */ |
| 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>™ |
| * 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 array 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; |
| } |