jdk/src/share/classes/javax/sql/rowset/JoinRowSet.java
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     1 /*
       
     2  * Copyright 2003-2004 Sun Microsystems, Inc.  All Rights Reserved.
       
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
       
     4  *
       
     5  * This code is free software; you can redistribute it and/or modify it
       
     6  * under the terms of the GNU General Public License version 2 only, as
       
     7  * published by the Free Software Foundation.  Sun designates this
       
     8  * particular file as subject to the "Classpath" exception as provided
       
     9  * by Sun in the LICENSE file that accompanied this code.
       
    10  *
       
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
       
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
       
    14  * version 2 for more details (a copy is included in the LICENSE file that
       
    15  * accompanied this code).
       
    16  *
       
    17  * You should have received a copy of the GNU General Public License version
       
    18  * 2 along with this work; if not, write to the Free Software Foundation,
       
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
       
    20  *
       
    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
       
    22  * CA 95054 USA or visit www.sun.com if you need additional information or
       
    23  * have any questions.
       
    24  */
       
    25 
       
    26 package javax.sql.rowset;
       
    27 
       
    28 import java.sql.*;
       
    29 import javax.sql.*;
       
    30 import javax.naming.*;
       
    31 import java.io.*;
       
    32 import java.math.*;
       
    33 import java.util.*;
       
    34 
       
    35 import javax.sql.rowset.*;
       
    36 
       
    37 /**
       
    38  * The <code>JoinRowSet</code> interface provides a mechanism for combining related
       
    39  * data from different <code>RowSet</code> objects into one <code>JoinRowSet</code>
       
    40  * object, which represents an SQL <code>JOIN</code>.
       
    41  * In other words, a <code>JoinRowSet</code> object acts as a
       
    42  * container for the data from <code>RowSet</code> objects that form an SQL
       
    43  * <code>JOIN</code> relationship.
       
    44  * <P>
       
    45  * The <code>Joinable</code> interface provides the methods for setting,
       
    46  * retrieving, and unsetting a match column, the basis for
       
    47  * establishing an SQL <code>JOIN</code> relationship. The match column may
       
    48  * alternatively be set by supplying it to the appropriate version of the
       
    49  * <code>JointRowSet</code> method <code>addRowSet</code>.
       
    50  * <P>
       
    51  * <p>
       
    52  * <h3>1.0 Overview</h3>
       
    53  * Disconnected <code>RowSet</code> objects (<code>CachedRowSet</code> objects
       
    54  * and implementations extending the <code>CachedRowSet</code> interface)
       
    55  * do not have a standard way to establish an SQL <code>JOIN</code> between
       
    56  * <code>RowSet</code> objects without the expensive operation of
       
    57  * reconnecting to the data source. The <code>JoinRowSet</code>
       
    58  * interface is specifically designed to address this need.
       
    59  * <P>
       
    60  * Any <code>RowSet</code> object
       
    61  * can be added to a <code>JoinRowSet</code> object to become
       
    62  * part of an SQL <code>JOIN</code> relationship. This means that both connected
       
    63  * and disconnected <code>RowSet</code> objects can be part of a <code>JOIN</code>.
       
    64  * <code>RowSet</code> objects operating in a connected environment
       
    65  * (<code>JdbcRowSet</code> objects) are
       
    66  * encouraged to use the database to which they are already
       
    67  * connected to establish SQL <code>JOIN</code> relationships between
       
    68  * tables directly. However, it is possible for a
       
    69  * <code>JdbcRowSet</code> object to be added to a <code>JoinRowSet</code> object
       
    70  * if necessary.
       
    71  * <P>
       
    72  * Any number of <code>RowSet</code> objects can be added to an
       
    73  * instance of <code>JoinRowSet</code> provided that they
       
    74  * can be related in an SQL <code>JOIN</code>.
       
    75  * By definition, the SQL <code>JOIN</code> statement is used to
       
    76  * combine the data contained in two or more relational database tables based
       
    77  * upon a common attribute. The <code>Joinable</code> interface provides the methods
       
    78  * for establishing a common attribute, which is done by setting a
       
    79  * <i>match column</i>. The match column commonly coincides with
       
    80  * the primary key, but there is
       
    81  * no requirement that the match column be the same as the primary key.
       
    82  * By establishing and then enforcing column matches,
       
    83  * a <code>JoinRowSet</code> object establishes <code>JOIN</code> relationships
       
    84  * between <code>RowSet</code> objects without the assistance of an available
       
    85  * relational database.
       
    86  * <P>
       
    87  * The type of <code>JOIN</code> to be established is determined by setting
       
    88  * one of the <code>JoinRowSet</code> constants using the method
       
    89  * <code>setJoinType</code>. The following SQL <code>JOIN</code> types can be set:
       
    90  * <UL>
       
    91  *  <LI><code>CROSS_JOIN</code>
       
    92  *  <LI><code>FULL_JOIN</code>
       
    93  *  <LI><code>INNER_JOIN</code> - the default if no <code>JOIN</code> type has been set
       
    94  *  <LI><code>LEFT_OUTER_JOIN</code>
       
    95  *  <LI><code>RIGHT_OUTER_JOIN</code>
       
    96  * </UL>
       
    97  * Note that if no type is set, the <code>JOIN</code> will automatically be an
       
    98  * inner join. The comments for the fields in the
       
    99  * <code>JoinRowSet</code> interface explain these <code>JOIN</code> types, which are
       
   100  * standard SQL <code>JOIN</code> types.
       
   101  * <P>
       
   102  * <h3>2.0 Using a <code>JoinRowSet</code> Object for Creating a <code>JOIN</code></h3>
       
   103  * When a <code>JoinRowSet</code> object is created, it is empty.
       
   104  * The first <code>RowSet</code> object to be added becomes the basis for the
       
   105  * <code>JOIN</code> relationship.
       
   106  * Applications must determine which column in each of the
       
   107  * <code>RowSet</code> objects to be added to the <code>JoinRowSet</code> object
       
   108  * should be the match column. All of the
       
   109  * <code>RowSet</code> objects must contain a match column, and the values in
       
   110  * each match column must be ones that can be compared to values in the other match
       
   111  * columns. The columns do not have to have the same name, though they often do,
       
   112  * and they do not have to store the exact same data type as long as the data types
       
   113  * can be compared.
       
   114  * <P>
       
   115  * A match column can be be set in two ways:
       
   116  * <ul>
       
   117  *  <li>By calling the <code>Joinable</code> method <code>setMatchColumn</code><br>
       
   118  *  This is the only method that can set the match column before a <code>RowSet</code>
       
   119  *  object is added to a <code>JoinRowSet</code> object. The <code>RowSet</code> object
       
   120  *  must have implemented the <code>Joinable</code> interface in order to use the method
       
   121  *  <code>setMatchColumn</code>. Once the match column value
       
   122  *  has been set, this method can be used to reset the match column at any time.
       
   123  *  <li>By calling one of the versions of the <code>JoinRowSet</code> method
       
   124  *  <code>addRowSet</code> that takes a column name or number (or an array of
       
   125  *  column names or numbers)<BR>
       
   126  *  Four of the five <code>addRowSet</code> methods take a match column as a parameter.
       
   127  *  These four methods set or reset the match column at the time a <code>RowSet</code>
       
   128  *  object is being added to a <code>JoinRowSet</code> object.
       
   129  * </ul>
       
   130  * <h3>3.0 Sample Usage</h3>
       
   131  * <p>
       
   132  * The following code fragment adds two <code>CachedRowSet</code>
       
   133  * objects to a <code>JoinRowSet</code> object. Note that in this example,
       
   134  * no SQL <code>JOIN</code> type is set, so the default <code>JOIN</code> type,
       
   135  * which is <i>INNER_JOIN</i>, is established.
       
   136  * <p>
       
   137  * In the following code fragment, the table <code>EMPLOYEES</code>, whose match
       
   138  * column is set to the first column (<code>EMP_ID</code>), is added to the
       
   139  * <code>JoinRowSet</code> object <i>jrs</i>. Then
       
   140  * the table <code>ESSP_BONUS_PLAN</code>, whose match column is likewise
       
   141  * the <code>EMP_ID</code> column, is added. When this second
       
   142  * table is added to <i>jrs</i>, only the rows in
       
   143  * <code>ESSP_BONUS_PLAN</code> whose <code>EMP_ID</code> value matches an
       
   144  * <code>EMP_ID</code> value in the <code>EMPLOYEES</code> table are added.
       
   145  * In this case, everyone in the bonus plan is an employee, so all of the rows
       
   146  * in the table <code>ESSP_BONUS_PLAN</code> are added to the <code>JoinRowSet</code>
       
   147  * object.  In this example, both <code>CachedRowSet</code> objects being added
       
   148  * have implemented the <code>Joinable</code> interface and can therefore call
       
   149  * the <code>Joinable</code> method <code>setMatchColumn</code>.
       
   150  * <PRE>
       
   151  *     JoinRowSet jrs = new JoinRowSetImpl();
       
   152  *
       
   153  *     ResultSet rs1 = stmt.executeQuery("SELECT * FROM EMPLOYEES");
       
   154  *     CachedRowSet empl = new CachedRowSetImpl();
       
   155  *     empl.populate(rs1);
       
   156  *     empl.setMatchColumn(1);
       
   157  *     jrs.addRowSet(empl);
       
   158  *
       
   159  *     ResultSet rs2 = stmt.executeQuery("SELECT * FROM ESSP_BONUS_PLAN");
       
   160  *     CachedRowSet bonus = new CachedRowSetImpl();
       
   161  *     bonus.populate(rs2);
       
   162  *     bonus.setMatchColumn(1); // EMP_ID is the first column
       
   163  *     jrs.addRowSet(bonus);
       
   164  * </PRE>
       
   165  * <P>
       
   166  * At this point, <i>jrs</i> is an inside JOIN of the two <code>RowSet</code> objects
       
   167  * based on their <code>EMP_ID</code> columns. The application can now browse the
       
   168  * combined data as if it were browsing one single <code>RowSet</code> object.
       
   169  * Because <i>jrs</i> is itself a <code>RowSet</code> object, an application can
       
   170  * navigate or modify it using <code>RowSet</code> methods.
       
   171  * <PRE>
       
   172  *     jrs.first();
       
   173  *     int employeeID = jrs.getInt(1);
       
   174  *     String employeeName = jrs.getString(2);
       
   175  * </PRE>
       
   176  * <P>
       
   177  * Note that because the SQL <code>JOIN</code> must be enforced when an application
       
   178  * adds a second or subsequent <code>RowSet</code> object, there
       
   179  * may be an initial degradation in performance while the <code>JOIN</code> is
       
   180  * being performed.
       
   181  * <P>
       
   182  * The following code fragment adds an additional <code>CachedRowSet</code> object.
       
   183  * In this case, the match column (<code>EMP_ID</code>) is set when the
       
   184  * <code>CachedRowSet</code> object is added to the <code>JoinRowSet</code> object.
       
   185  * <PRE>
       
   186  *     ResultSet rs3 = stmt.executeQuery("SELECT * FROM 401K_CONTRIB");
       
   187  *     CachedRowSet fourO1k = new CachedRowSetImpl();
       
   188  *     four01k.populate(rs3);
       
   189  *     jrs.addRowSet(four01k, 1);
       
   190  * </PRE>
       
   191  * <P>
       
   192  * The <code>JoinRowSet</code> object <i>jrs</i> now contains values from all three
       
   193  * tables. The data in each row in <i>four01k</i> in which the value for the
       
   194  * <code>EMP_ID</code> column matches a value for the <code>EMP_ID</code> column
       
   195  * in <i>jrs</i> has been added to <i>jrs</i>.
       
   196  * <P>
       
   197  * <h3>4.0 <code>JoinRowSet</code> Methods</h3>
       
   198  * The <code>JoinRowSet</code> interface supplies several methods for adding
       
   199  * <code>RowSet</code> objects and for getting information about the
       
   200  * <code>JoinRowSet</code> object.
       
   201  * <UL>
       
   202  *   <LI>Methods for adding one or more <code>RowSet</code> objects<BR>
       
   203  *       These methods allow an application to add one <code>RowSet</code> object
       
   204  *       at a time or to add multiple <code>RowSet</code> objects at one time. In
       
   205  *       either case, the methods may specify the match column for each
       
   206  *       <code>RowSet</code> object being added.
       
   207  *   <LI>Methods for getting information<BR>
       
   208  *       One method retrieves the <code>RowSet</code> objects in the
       
   209  *       <code>JoinRowSet</code> object, and another method retrieves the
       
   210  *       <code>RowSet</code> names.  A third method retrieves either the SQL
       
   211  *       <code>WHERE</code> clause used behind the scenes to form the
       
   212  *       <code>JOIN</code> or a text description of what the <code>WHERE</code>
       
   213  *       clause does.
       
   214  *   <LI>Methods related to the type of <code>JOIN</code><BR>
       
   215  *       One method sets the <code>JOIN</code> type, and five methods find out whether
       
   216  *       the <code>JoinRowSet</code> object supports a given type.
       
   217  *   <LI>A method to make a separate copy of the <code>JoinRowSet</code> object<BR>
       
   218  *       This method creates a copy that can be persisted to the data source.
       
   219  * </UL>
       
   220  * <P>
       
   221  */
       
   222 
       
   223 public interface JoinRowSet extends WebRowSet {
       
   224 
       
   225     /**
       
   226      * Adds the given <code>RowSet</code> object to this <code>JoinRowSet</code>
       
   227      * object. If the <code>RowSet</code> object
       
   228      * is the first to be added to this <code>JoinRowSet</code>
       
   229      * object, it forms the basis of the <code>JOIN</code> relationship to be
       
   230      * established.
       
   231      * <P>
       
   232      * This method should be used only when the given <code>RowSet</code>
       
   233      * object already has a match column that was set with the <code>Joinable</code>
       
   234      * method <code>setMatchColumn</code>.
       
   235      * <p>
       
   236      * Note: A <code>Joinable</code> object is any <code>RowSet</code> object
       
   237      * that has implemented the <code>Joinable</code> interface.
       
   238      *
       
   239      * @param rowset the <code>RowSet</code> object that is to be added to this
       
   240      *        <code>JoinRowSet</code> object; it must implement the
       
   241      *        <code>Joinable</code> interface and have a match column set
       
   242      * @throws SQLException if (1) an empty rowset is added to the to this
       
   243      *         <code>JoinRowSet</code> object, (2) a match column has not been
       
   244      *         set for <i>rowset</i>, or (3) <i>rowset</i>
       
   245      *         violates the active <code>JOIN</code>
       
   246      * @see Joinable#setMatchColumn
       
   247      */
       
   248     public void addRowSet(Joinable rowset) throws SQLException;
       
   249 
       
   250     /**
       
   251      * Adds the given <code>RowSet</code> object to this <code>JoinRowSet</code>
       
   252      * object and sets the designated column as the match column for
       
   253      * the <code>RowSet</code> object. If the <code>RowSet</code> object
       
   254      * is the first to be added to this <code>JoinRowSet</code>
       
   255      * object, it forms the basis of the <code>JOIN</code> relationship to be
       
   256      * established.
       
   257      * <P>
       
   258      * This method should be used when <i>RowSet</i> does not already have a match
       
   259      * column set.
       
   260      *
       
   261      * @param rowset the <code>RowSet</code> object that is to be added to this
       
   262      *        <code>JoinRowSet</code> object; it may implement the
       
   263      *        <code>Joinable</code> interface
       
   264      * @param columnIdx an <code>int</code> that identifies the column to become the
       
   265      *         match column
       
   266      * @throws SQLException if (1) <i>rowset</i> is an empty rowset or
       
   267      *         (2) <i>rowset</i> violates the active <code>JOIN</code>
       
   268      * @see Joinable#unsetMatchColumn
       
   269      */
       
   270     public void addRowSet(RowSet rowset, int columnIdx) throws SQLException;
       
   271 
       
   272     /**
       
   273      * Adds <i>rowset</i> to this <code>JoinRowSet</code> object and
       
   274      * sets the designated column as the match column. If <i>rowset</i>
       
   275      * is the first to be added to this <code>JoinRowSet</code>
       
   276      * object, it forms the basis for the <code>JOIN</code> relationship to be
       
   277      * established.
       
   278      * <P>
       
   279      * This method should be used when the given <code>RowSet</code> object
       
   280      * does not already have a match column.
       
   281      *
       
   282      * @param rowset the <code>RowSet</code> object that is to be added to this
       
   283      *        <code>JoinRowSet</code> object; it may implement the
       
   284      *        <code>Joinable</code> interface
       
   285      * @param columnName the <code>String</code> object giving the name of the
       
   286      *        column to be set as the match column
       
   287      * @throws SQLException if (1) <i>rowset</i> is an empty rowset or
       
   288      *         (2) the match column for <i>rowset</i> does not satisfy the
       
   289      *         conditions of the <code>JOIN</code>
       
   290      */
       
   291      public void addRowSet(RowSet rowset,
       
   292                            String columnName) throws SQLException;
       
   293 
       
   294     /**
       
   295      * Adds one or more <code>RowSet</code> objects contained in the given
       
   296      * array of <code>RowSet</code> objects to this <code>JoinRowSet</code>
       
   297      * object and sets the match column for
       
   298      * each of the <code>RowSet</code> objects to the match columns
       
   299      * in the given array of column indexes. The first element in
       
   300      * <i>columnIdx</i> is set as the match column for the first
       
   301      * <code>RowSet</code> object in <i>rowset</i>, the second element of
       
   302      * <i>columnIdx</i> is set as the match column for the second element
       
   303      * in <i>rowset</i>, and so on.
       
   304      * <P>
       
   305      * The first <code>RowSet</code> object added to this <code>JoinRowSet</code>
       
   306      * object forms the basis for the <code>JOIN</code> relationship.
       
   307      * <P>
       
   308      * This method should be used when the given <code>RowSet</code> object
       
   309      * does not already have a match column.
       
   310      *
       
   311      * @param rowset an array of one or more <code>RowSet</code> objects
       
   312      *        to be added to the <code>JOIN</code>; it may implement the
       
   313      *        <code>Joinable</code> interface
       
   314      * @param columnIdx an array of <code>int</code> values indicating the index(es)
       
   315      *        of the columns to be set as the match columns for the <code>RowSet</code>
       
   316      *        objects in <i>rowset</i>
       
   317      * @throws SQLException if (1) an empty rowset is added to this
       
   318      *         <code>JoinRowSet</code> object, (2) a match column is not set
       
   319      *         for a <code>RowSet</code> object in <i>rowset</i>, or (3)
       
   320      *         a <code>RowSet</code> object being added violates the active
       
   321      *         <code>JOIN</code>
       
   322      */
       
   323     public void addRowSet(RowSet[] rowset,
       
   324                           int[] columnIdx) throws SQLException;
       
   325 
       
   326     /**
       
   327      * Adds one or more <code>RowSet</code> objects contained in the given
       
   328      * array of <code>RowSet</code> objects to this <code>JoinRowSet</code>
       
   329      * object and sets the match column for
       
   330      * each of the <code>RowSet</code> objects to the match columns
       
   331      * in the given array of column names. The first element in
       
   332      * <i>columnName</i> is set as the match column for the first
       
   333      * <code>RowSet</code> object in <i>rowset</i>, the second element of
       
   334      * <i>columnName</i> is set as the match column for the second element
       
   335      * in <i>rowset</i>, and so on.
       
   336      * <P>
       
   337      * The first <code>RowSet</code> object added to this <code>JoinRowSet</code>
       
   338      * object forms the basis for the <code>JOIN</code> relationship.
       
   339      * <P>
       
   340      * This method should be used when the given <code>RowSet</code> object(s)
       
   341      * does not already have a match column.
       
   342      *
       
   343      * @param rowset an array of one or more <code>RowSet</code> objects
       
   344      *        to be added to the <code>JOIN</code>; it may implement the
       
   345      *        <code>Joinable</code> interface
       
   346      * @param columnName an array of <code>String</code> values indicating the
       
   347      *        names of the columns to be set as the match columns for the
       
   348      *        <code>RowSet</code> objects in <i>rowset</i>
       
   349      * @throws SQLException if (1) an empty rowset is added to this
       
   350      *         <code>JoinRowSet</code> object, (2) a match column is not set
       
   351      *         for a <code>RowSet</code> object in <i>rowset</i>, or (3)
       
   352      *         a <code>RowSet</code> object being added violates the active
       
   353      *         <code>JOIN</code>
       
   354      */
       
   355     public void addRowSet(RowSet[] rowset,
       
   356                           String[] columnName) throws SQLException;
       
   357 
       
   358     /**
       
   359      * Returns a <code>Collection</code> object containing the
       
   360      * <code>RowSet</code> objects that have been added to this
       
   361      * <code>JoinRowSet</code> object.
       
   362      * This should return the 'n' number of RowSet contained
       
   363      * within the <code>JOIN</code> and maintain any updates that have occured while in
       
   364      * this union.
       
   365      *
       
   366      * @return a <code>Collection</code> object consisting of the
       
   367      *        <code>RowSet</code> objects added to this <code>JoinRowSet</code>
       
   368      *        object
       
   369      * @throws SQLException if an error occurs generating the
       
   370      *         <code>Collection</code> object to be returned
       
   371      */
       
   372     public Collection<?> getRowSets() throws java.sql.SQLException;
       
   373 
       
   374     /**
       
   375      * Returns a <code>String</code> array containing the names of the
       
   376      *         <code>RowSet</code> objects added to this <code>JoinRowSet</code>
       
   377      *         object.
       
   378      *
       
   379      * @return a <code>String</code> array of the names of the
       
   380      *         <code>RowSet</code> objects in this <code>JoinRowSet</code>
       
   381      *         object
       
   382      * @throws SQLException if an error occurs retrieving the names of
       
   383      *         the <code>RowSet</code> objects
       
   384      * @see CachedRowSet#setTableName
       
   385      */
       
   386     public String[] getRowSetNames() throws java.sql.SQLException;
       
   387 
       
   388     /**
       
   389      * Creates a new <code>CachedRowSet</code> object containing the
       
   390      * data in this <code>JoinRowSet</code> object, which can be saved
       
   391      * to a data source using the <code>SyncProvider</code> object for
       
   392      * the <code>CachedRowSet</code> object.
       
   393      * <P>
       
   394      * If any updates or modifications have been applied to the JoinRowSet
       
   395      * the CachedRowSet returned by the method will not be able to persist
       
   396      * it's changes back to the originating rows and tables in the
       
   397      * in the datasource. The CachedRowSet instance returned should not
       
   398      * contain modification data and it should clear all properties of
       
   399      * it's originating SQL statement. An application should reset the
       
   400      * SQL statement using the <code>RowSet.setCommand</code> method.
       
   401      * <p>
       
   402      * In order to allow changes to be persisted back to the datasource
       
   403      * to the originating tables, the <code>acceptChanges</code> method
       
   404      * should be used and called on a JoinRowSet object instance. Implementations
       
   405      * can leverage the internal data and update tracking in their
       
   406      * implementations to interact with the SyncProvider to persist any
       
   407      * changes.
       
   408      *
       
   409      * @return a CachedRowSet containing the contents of the JoinRowSet
       
   410      * @throws SQLException if an error occurs assembling the CachedRowSet
       
   411      * object
       
   412      * @see javax.sql.RowSet
       
   413      * @see javax.sql.rowset.CachedRowSet
       
   414      * @see javax.sql.rowset.spi.SyncProvider
       
   415      */
       
   416     public CachedRowSet toCachedRowSet() throws java.sql.SQLException;
       
   417 
       
   418     /**
       
   419      * Indicates if CROSS_JOIN is supported by a JoinRowSet
       
   420      * implementation
       
   421      *
       
   422      * @return true if the CROSS_JOIN is supported; false otherwise
       
   423      */
       
   424     public boolean supportsCrossJoin();
       
   425 
       
   426     /**
       
   427      * Indicates if INNER_JOIN is supported by a JoinRowSet
       
   428      * implementation
       
   429      *
       
   430      * @return true is the INNER_JOIN is supported; false otherwise
       
   431      */
       
   432     public boolean supportsInnerJoin();
       
   433 
       
   434     /**
       
   435      * Indicates if LEFT_OUTER_JOIN is supported by a JoinRowSet
       
   436      * implementation
       
   437      *
       
   438      * @return true is the LEFT_OUTER_JOIN is supported; false otherwise
       
   439      */
       
   440     public boolean supportsLeftOuterJoin();
       
   441 
       
   442     /**
       
   443      * Indicates if RIGHT_OUTER_JOIN is supported by a JoinRowSet
       
   444      * implementation
       
   445      *
       
   446      * @return true is the RIGHT_OUTER_JOIN is supported; false otherwise
       
   447      */
       
   448     public boolean supportsRightOuterJoin();
       
   449 
       
   450     /**
       
   451      * Indicates if FULL_JOIN is supported by a JoinRowSet
       
   452      * implementation
       
   453      *
       
   454      * @return true is the FULL_JOIN is supported; false otherwise
       
   455      */
       
   456     public boolean supportsFullJoin();
       
   457 
       
   458     /**
       
   459      * Allow the application to adjust the type of <code>JOIN</code> imposed
       
   460      * on tables contained within the JoinRowSet object instance.
       
   461      * Implementations should throw a SQLException if they do
       
   462      * not support a given <code>JOIN</code> type.
       
   463      *
       
   464      * @param joinType the standard JoinRowSet.XXX static field definition
       
   465      * of a SQL <code>JOIN</code> to re-configure a JoinRowSet instance on
       
   466      * the fly.
       
   467      * @throws SQLException if an unsupported <code>JOIN</code> type is set
       
   468      * @see #getJoinType
       
   469      */
       
   470     public void setJoinType(int joinType) throws SQLException;
       
   471 
       
   472     /**
       
   473      * Return a SQL-like description of the WHERE clause being used
       
   474      * in a JoinRowSet object. An implementation can describe
       
   475      * the WHERE clause of the SQL <code>JOIN</code> by supplying a SQL
       
   476      * strings description of <code>JOIN</code> or provide a textual
       
   477      * description to assist applications using a <code>JoinRowSet</code>
       
   478      *
       
   479      * @return whereClause a textual or SQL description of the logical
       
   480      * WHERE clause used in the JoinRowSet instance
       
   481      * @throws SQLException if an error occurs in generating a representation
       
   482      * of the WHERE clause.
       
   483      */
       
   484     public String getWhereClause() throws SQLException;
       
   485 
       
   486     /**
       
   487      * Returns a <code>int</code> describing the set SQL <code>JOIN</code> type
       
   488      * governing this JoinRowSet instance. The returned type will be one of
       
   489      * standard JoinRowSet types: <code>CROSS_JOIN</code>, <code>INNER_JOIN</code>,
       
   490      * <code>LEFT_OUTER_JOIN</code>, <code>RIGHT_OUTER_JOIN</code> or
       
   491      * <code>FULL_JOIN</code>.
       
   492      *
       
   493      * @return joinType one of the standard JoinRowSet static field
       
   494      *     definitions of a SQL <code>JOIN</code>. <code>JoinRowSet.INNER_JOIN</code>
       
   495      *     is returned as the default <code>JOIN</code> type is no type has been
       
   496      *     explicitly set.
       
   497      * @throws SQLException if an error occurs determining the SQL <code>JOIN</code>
       
   498      *     type supported by the JoinRowSet instance.
       
   499      * @see #setJoinType
       
   500      */
       
   501     public int getJoinType() throws SQLException;
       
   502 
       
   503     /**
       
   504      * An ANSI-style <code>JOIN</code> providing a cross product of two tables
       
   505      */
       
   506     public static int CROSS_JOIN = 0;
       
   507 
       
   508     /**
       
   509      * An ANSI-style <code>JOIN</code> providing a inner join between two tables. Any
       
   510      * unmatched rows in either table of the join should be discarded.
       
   511      */
       
   512     public static int INNER_JOIN = 1;
       
   513 
       
   514     /**
       
   515      * An ANSI-style <code>JOIN</code> providing a left outer join between two
       
   516      * tables. In SQL, this is described where all records should be
       
   517      * returned from the left side of the JOIN statement.
       
   518      */
       
   519     public static int LEFT_OUTER_JOIN = 2;
       
   520 
       
   521     /**
       
   522      * An ANSI-style <code>JOIN</code> providing a right outer join between
       
   523      * two tables. In SQL, this is described where all records from the
       
   524      * table on the right side of the JOIN statement even if the table
       
   525      * on the left has no matching record.
       
   526      */
       
   527     public static int RIGHT_OUTER_JOIN = 3;
       
   528 
       
   529     /**
       
   530      * An ANSI-style <code>JOIN</code> providing a a full JOIN. Specifies that all
       
   531      * rows from either table be returned regardless of matching
       
   532      * records on the other table.
       
   533      */
       
   534     public static int FULL_JOIN = 4;
       
   535 
       
   536 
       
   537 }