112  * interface).
 113  * <pre>
 114  *     int[] w = {3, 2, 5, 3};
 115  *     Joinable2.setMatchColumn(w);
 116  * </pre>
 117  * When an application adds two or more <code>RowSet</code> objects to a
 118  * <code>JoinRowSet</code> object, the order of the indexes in the array is
 119  * particularly important. Each index of
 120  * the array maps directly to the corresponding index of the previously added
 121  * <code>RowSet</code> object. If overlap or underlap occurs, the match column
 122  * data is maintained in the event an additional <code>Joinable</code> RowSet is
 123  * added and needs to relate to the match column data. Therefore, applications
 124  * can set multiple match columns in any order, but
 125  * this order has a direct effect on the outcome of the <code>SQL</code> JOIN.
 126  * <p>
 127  * This assertion applies in exactly the same manner when column names are used
 128  * rather than column indexes to indicate match columns.
 129  *
 130  * @see JoinRowSet
 131  * @author  Jonathan Bruce

 132  */
 133 public interface Joinable {
 134 
 135     /**
 136      * Sets the designated column as the match column for this <code>RowSet</code>
 137      * object. A <code>JoinRowSet</code> object can now add this <code>RowSet</code>
 138      * object based on the match column.
 139      * <p>
 140      * Sub-interfaces such as the <code>CachedRowSet</code>&trade;
 141      * interface define the method <code>CachedRowSet.setKeyColumns</code>, which allows
 142      * primary key semantics to be enforced on specific columns.
 143      * Implementations of the <code>setMatchColumn(int columnIdx)</code> method
 144      * should ensure that the constraints on the key columns are maintained when
 145      * a <code>CachedRowSet</code> object sets a primary key column as a match column.
 146      *
 147      * @param columnIdx an <code>int</code> identifying the index of the column to be
 148      *        set as the match column
 149      * @throws SQLException if an invalid column index is set
 150      * @see #setMatchColumn(int[])
 151      * @see #unsetMatchColumn(int)

 112  * interface).
 113  * <pre>
 114  *     int[] w = {3, 2, 5, 3};
 115  *     Joinable2.setMatchColumn(w);
 116  * </pre>
 117  * When an application adds two or more <code>RowSet</code> objects to a
 118  * <code>JoinRowSet</code> object, the order of the indexes in the array is
 119  * particularly important. Each index of
 120  * the array maps directly to the corresponding index of the previously added
 121  * <code>RowSet</code> object. If overlap or underlap occurs, the match column
 122  * data is maintained in the event an additional <code>Joinable</code> RowSet is
 123  * added and needs to relate to the match column data. Therefore, applications
 124  * can set multiple match columns in any order, but
 125  * this order has a direct effect on the outcome of the <code>SQL</code> JOIN.
 126  * <p>
 127  * This assertion applies in exactly the same manner when column names are used
 128  * rather than column indexes to indicate match columns.
 129  *
 130  * @see JoinRowSet
 131  * @author  Jonathan Bruce
 132  * @since 1.5
 133  */
 134 public interface Joinable {
 135 
 136     /**
 137      * Sets the designated column as the match column for this <code>RowSet</code>
 138      * object. A <code>JoinRowSet</code> object can now add this <code>RowSet</code>
 139      * object based on the match column.
 140      * <p>
 141      * Sub-interfaces such as the <code>CachedRowSet</code>&trade;
 142      * interface define the method <code>CachedRowSet.setKeyColumns</code>, which allows
 143      * primary key semantics to be enforced on specific columns.
 144      * Implementations of the <code>setMatchColumn(int columnIdx)</code> method
 145      * should ensure that the constraints on the key columns are maintained when
 146      * a <code>CachedRowSet</code> object sets a primary key column as a match column.
 147      *
 148      * @param columnIdx an <code>int</code> identifying the index of the column to be
 149      *        set as the match column
 150      * @throws SQLException if an invalid column index is set
 151      * @see #setMatchColumn(int[])
 152      * @see #unsetMatchColumn(int)