001    /* Connection.java -- Manage a database connection.
002       Copyright (C) 1999, 2000, 2002, 2006 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010     
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.sql;
040    
041    import java.util.Map;
042    
043    /**
044     * This interface provides methods for managing a connection to a database.
045     *
046     * @author Aaron M. Renn (arenn@urbanophile.com)
047     */
048    public interface Connection 
049    {
050      /**
051       * This transaction isolation level indicates that transactions are not
052       * supported.
053       */
054      int TRANSACTION_NONE = 0;
055    
056      /**
057       * This transaction isolation level indicates that one transaction can
058       * read modifications by other transactions before the other transactions
059       * have committed their changes.  This could result in invalid reads.
060       */
061      int TRANSACTION_READ_UNCOMMITTED = 1;
062    
063      /**
064       * This transaction isolation level indicates that only committed data from
065       * other transactions will be read.  If a transaction reads a row, then
066       * another transaction commits a change to that row, the first transaction
067       * would retrieve the changed row on subsequent reads of the same row.
068       */
069      int TRANSACTION_READ_COMMITTED = 2;
070    
071      /**
072       * This transaction isolation level indicates that only committed data from
073       * other transactions will be read.  It also ensures that data read from
074       * a row will not be different on a subsequent read even if another
075       * transaction commits a change.
076       */
077      int TRANSACTION_REPEATABLE_READ = 4;
078    
079      /**
080       * This transaction isolation level indicates that only committed data from
081       * other transactions will be read.  It also ensures that data read from
082       * a row will not be different on a subsequent read even if another
083       * transaction commits a change.  Additionally, rows modified by other
084       * transactions will not affect the result set returned during subsequent
085       * executions of the same WHERE clause in this transaction.
086       */
087      int TRANSACTION_SERIALIZABLE = 8;
088    
089      /**
090       * This method creates a new SQL statement.  The default result set type
091       * and concurrency will be used.
092       *
093       * @return A new <code>Statement</code> object. 
094       * @exception SQLException If an error occurs.
095       * @see Statement
096       */
097      Statement createStatement() throws SQLException;
098    
099      /**
100       * This method creates a new <code>PreparedStatement</code> for the specified
101       * SQL string.  This method is designed for use with parameterized
102       * statements.  The default result set type and concurrency will be used.
103       *
104       * @param sql The SQL statement to use in creating this 
105       *            <code>PreparedStatement</code>.
106       * @return A new <code>PreparedStatement</code>.
107       * @exception SQLException If an error occurs.
108       * @see PreparedStatement
109       */
110      PreparedStatement prepareStatement(String sql) throws SQLException;
111    
112      /**
113       * This method creates a new <code>CallableStatement</code> for the 
114       * specified SQL string.  Thie method is designed to be used with
115       * stored procedures.  The default result set type and concurrency
116       * will be used.
117       *
118       * @param sql The SQL statement to use in creating this 
119       *            <code>CallableStatement</code>.
120       * @return A new <code>CallableStatement</code>.
121       * @exception SQLException If an error occurs.
122       * @see CallableStatement
123       */
124      CallableStatement prepareCall(String sql) throws SQLException;
125    
126      /**
127       * This method converts the specified generic SQL statement into the
128       * native grammer of the database this object is connected to.
129       *
130       * @param sql The JDBC generic SQL statement.
131       * @return The native SQL statement.
132       * @exception SQLException If an error occurs.
133       */
134      String nativeSQL(String sql) throws SQLException;
135    
136      /**
137       * This method turns auto commit mode on or off.  In auto commit mode,
138       * every SQL statement is committed its own transaction.  Otherwise a
139       * transaction must be explicitly committed or rolled back.
140       *
141       * @param autoCommit <code>true</code> to enable auto commit mode,
142       *                   <code>false</code> to disable it.
143       * @exception SQLException If an error occurs.
144       * @see #commit()
145       * @see #rollback()
146       */
147      void setAutoCommit(boolean autoCommit) throws SQLException;
148    
149      /**
150       * This method tests whether or not auto commit mode is currently enabled.
151       * In auto commit mode,  every SQL statement is committed its own transaction.
152       * Otherwise a transaction must be explicitly committed or rolled back.
153       *
154       * @return <code>true</code> if auto commit mode is enabled, 
155       *         <code>false</code> otherwise.
156       * @exception SQLException If an error occurs.
157       * @see #commit()
158       * @see #rollback()
159       */
160      boolean getAutoCommit() throws SQLException;
161    
162     /**
163      * This method commits any SQL statements executed on this connection since 
164      * the last commit or rollback.
165      *
166      * @exception SQLException If an error occurs.
167      */
168      void commit() throws SQLException;
169    
170      /**
171       * This method rolls back any SQL statements executed on this connection
172       * since the last commit or rollback.
173       *
174       * @exception SQLException If an error occurs.
175       */
176      void rollback() throws SQLException;
177    
178      /**
179       * This method immediately closes this database connection.
180       *
181       * @exception SQLException If an error occurs.
182       */
183      void close() throws SQLException;
184    
185      /**
186       * This method tests whether or not this connection has been closed. 
187       *
188       * @return <code>true</code> if the connection is closed, <code>false</code>
189       *         otherwise.
190       * @exception SQLException If an error occurs.
191       */
192      boolean isClosed() throws SQLException;
193    
194      /**
195       * This method returns the meta data for this database connection.
196       *
197       * @return The meta data for this database.
198       * @exception SQLException If an error occurs.
199       * @see DatabaseMetaData
200       */
201      DatabaseMetaData getMetaData() throws SQLException;
202    
203      /**
204       * This method turns read only mode on or off.  It may not be called while
205       * a transaction is in progress.
206       *
207       * @param readOnly <code>true</code> if this connection is read only,
208       *                 <code>false</code> otherwise.
209       * @exception SQLException If an error occurs.
210       */
211      void setReadOnly(boolean readOnly) throws SQLException;
212    
213      /**
214       * This method tests whether or not this connection is in read only mode.
215       *
216       * @return <code>true</code> if the connection is read only <code>false</code>
217       *         otherwise.
218       * @exception SQLException If an error occurs.
219       */
220      boolean isReadOnly() throws SQLException;
221    
222      /**
223       * This method sets the name of the catalog in use by this connection.
224       * Note that this method does nothing if catalogs are not supported by
225       * this database.
226       *
227       * @param catalog The name of the catalog to use for this connection.
228       * @exception SQLException If an error occurs.
229       */
230      void setCatalog(String catalog) throws SQLException;
231    
232      /**
233       * This method returns the name of the catalog in use by this connection,
234       * if any.
235       *
236       * @return The name of the catalog, or <code>null</code> if none 
237       *         exists or catalogs are not supported by this database.
238       * @exception SQLException If an error occurs.
239       */
240      String getCatalog() throws SQLException;
241    
242      /**
243       * This method sets the current transaction isolation mode.  This must
244       * be one of the constants defined in this interface.
245       *
246       * @param level The transaction isolation level.
247       * @exception SQLException If an error occurs.
248       */
249      void setTransactionIsolation(int level) throws SQLException;
250    
251      /**
252       * This method returns the current transaction isolation mode.  This will
253       * be one of the constants defined in this interface.
254       *
255       * @return The transaction isolation level.
256       * @exception SQLException If an error occurs.
257       */
258      int getTransactionIsolation() throws SQLException;
259    
260      /**
261       * This method returns the first warning that occurred on this connection,
262       * if any.  If there were any subsequence warnings, they will be chained
263       * to the first one.
264       *
265       * @return The first <code>SQLWarning</code> that occurred, or 
266       *         <code>null</code> if there have been no warnings.
267       * @exception SQLException If an error occurs.
268       */
269      SQLWarning getWarnings() throws SQLException;
270    
271      /**
272       * This method clears all warnings that have occurred on this connection.
273       *
274       * @exception SQLException If an error occurs.
275       */
276      void clearWarnings() throws SQLException;
277    
278      /**
279       * This method creates a new SQL statement with the specified type and
280       * concurrency.  Valid values for these parameters are specified in the
281       * <code>ResultSet</code> class.
282       *
283       * @param resultSetType The type of result set to use for this statement.
284       * @param resultSetConcurrency  The type of concurrency to be used in
285       *                              the result set for this statement.
286       * @return A new <code>Statement</code> object.
287       * @exception SQLException If an error occurs.
288       * @see Statement
289       * @see ResultSet
290       */
291      Statement createStatement(int resultSetType, int resultSetConcurrency)
292        throws SQLException;
293    
294      /**
295       * This method creates a new <code>PreparedStatement</code> for the specified
296       * SQL string.  This method is designed for use with parameterized
297       * statements.  The specified result set type and concurrency will be used.
298       * Valid values for these parameters are specified in the
299       * <code>ResultSet</code> class.
300       *
301       * @param sql The SQL statement to use in creating this 
302       *            <code>PreparedStatement</code>.
303       * @param resultSetType The type of result set to use for this statement.
304       * @param resultSetConcurrency  The type of concurrency to be used in
305       *                              the result set for this statement.
306       * @return A new <code>PreparedStatement</code>.
307       * @exception SQLException If an error occurs.
308       * @see PreparedStatement
309       * @see ResultSet
310       */
311      PreparedStatement prepareStatement(String sql, int resultSetType, 
312        int resultSetConcurrency) throws SQLException;
313    
314      /**
315       * This method creates a new <code>CallableStatement</code> for the 
316       * specified SQL string.  Thie method is designed to be used with
317       * stored procedures.  The specified result set type and concurrency
318       * will be used.  Valid values for these parameters are specified in the
319       * <code>ResultSet</code> class.
320       *
321       * @param sql The SQL statement to use in creating this 
322       *            <code>PreparedStatement</code>.
323       * @param resultSetType The type of result set to use for this statement.
324       * @param resultSetConcurrency  The type of concurrency to be used in
325       *                              the result set for this statement.
326       * @return A new <code>CallableStatement</code>.
327       * @exception SQLException If an error occurs.
328       * @see CallableStatement
329       * @see ResultSet
330       */
331      CallableStatement prepareCall(String sql, int resultSetType, int
332        resultSetConcurrency) throws SQLException;
333    
334      /**
335       * This method returns the mapping of SQL types to Java classes
336       * currently in use by this connection.  This mapping will have no
337       * entries unless they have been manually added.
338       *
339       * @return The SQL type to Java class mapping.
340       * @exception SQLException If an error occurs.
341       */
342      Map<String, Class<?>> getTypeMap() throws SQLException;
343    
344      /**
345       * This method sets the mapping table for SQL types to Java classes.
346       * Any entries in this map override the defaults.
347       *
348       * @param map The new SQL mapping table.
349       * @exception SQLException If an error occurs.
350       */
351      void setTypeMap(Map<String, Class<?>> map) throws SQLException;
352    
353      /**
354       * Sets the default holdability of <code>ResultSet</code>S that are created
355       * from <code>Statement</code>S using this <code>Connection</code>.
356       * 
357       * @param holdability The default holdability value to set, this must be one
358       *                    of <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or
359       *                    <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>.
360       * @exception SQLException If an error occurs.
361       * @see ResultSet
362       * @since 1.4
363       */
364      void setHoldability(int holdability) throws SQLException;
365    
366      /**
367       * Gets the default holdability of <code>ResultSet</code>S that are created
368       * from <code>Statement</code>S using this <code>Connection</code>.
369       * 
370       * @return The current default holdability value, this must be one of
371       *          <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or
372       *          <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>.
373       * @exception SQLException If an error occurs.
374       * @see ResultSet
375       * @since 1.4
376       */
377      int getHoldability() throws SQLException;
378    
379      /**
380       * Creates a new unnamed savepoint for this <code>Connection</code>
381       * 
382       * @return The <code>Savepoint</code> object representing the savepoint.
383       * @exception SQLException If an error occurs.
384       * @since 1.4
385       */
386      Savepoint setSavepoint() throws SQLException;
387    
388      /**
389       * Creates a new savepoint with the specifiend name for this
390       * <code>Connection</code>.
391       * 
392       * @param name The name of the savepoint.
393       * @return The <code>Savepoint</code> object representing the savepoint.
394       * @exception SQLException If an error occurs.
395       * @since 1.4
396       */
397      Savepoint setSavepoint(String name) throws SQLException;
398    
399      /**
400       * Undoes all changes made after the specified savepoint was set.
401       * 
402       * @param savepoint The safepoint to roll back to.
403       * @exception SQLException If an error occurs.
404       * @since 1.4
405       */
406      void rollback(Savepoint savepoint) throws SQLException;
407    
408      /**
409       * Removes the specified savepoint from this <code>Connection</code>.
410       * Refering to a savepoint after it was removed is an error and will throw an
411       * SQLException.
412       * 
413       * @param savepoint The savepoint to release.
414       * @exception SQLException If an error occurs.
415       * @since 1.4
416       */
417      void releaseSavepoint(Savepoint savepoint) throws SQLException;
418    
419      /**
420       * This method creates a new SQL statement with the specified type,
421       * concurrency and holdability, instead of using the defaults.  Valid values
422       * for these parameters are specified in the <code>ResultSet</code> class.
423       * 
424       * @param resultSetType The type of result set to use for this statement.
425       * @param resultSetConcurrency The type of concurrency to be used in
426       *                             the result set for this statement.
427       * @param resultSetHoldability The type of holdability to be usd in the
428       *                             result set for this statement.
429       * @return A new <code>Statement</code>
430       * @exception SQLException If an error occurs.
431       * @see ResultSet
432       * @since 1.4
433       */
434      Statement createStatement(int resultSetType, int
435          resultSetConcurrency, int resultSetHoldability) throws SQLException;
436    
437      /**
438       * This method creates a new <code>PreparedStatement</code> for the specified
439       * SQL string.  This method is designed for use with parameterized
440       * statements.  The specified result set type, concurrency and holdability
441       * will be used. Valid values for these parameters are specified in the
442       * <code>ResultSet</code> class.
443       *
444       * @param sql The SQL statement to use in creating this 
445       *            <code>PreparedStatement</code>.
446       * @param resultSetType The type of result set to use for this statement.
447       * @param resultSetConcurrency The type of concurrency to be used in
448       *                             the result set for this statement.
449       * @param resultSetHoldability The type of holdability to be usd in the
450       *                             result set for this statement.
451       * @return A new <code>PreparedStatement</code>.
452       * @exception SQLException If an error occurs.
453       * @see PreparedStatement
454       * @see ResultSet
455       * @since 1.4
456       */
457      PreparedStatement prepareStatement(String sql, int resultSetType, int
458          resultSetConcurrency, int resultSetHoldability) throws SQLException;
459    
460      /**
461       * This method creates a new <code>CallableStatement</code> for the 
462       * specified SQL string.  Thie method is designed to be used with
463       * stored procedures.  The specified result set type, concurrency and
464       * holdability will be used.  Valid values for these parameters are specified
465       * in the <code>ResultSet</code> class.
466       *
467       * @param sql The SQL statement to use in creating this 
468       *            <code>PreparedStatement</code>.
469       * @param resultSetType The type of result set to use for this statement.
470       * @param resultSetConcurrency The type of concurrency to be used in
471       *                             the result set for this statement.
472       * @param resultSetHoldability The type of holdability to be used in the
473       *                             result set for this statement.
474       * @return A new <code>CallableStatement</code>.
475       * @exception SQLException If an error occurs.
476       * @see CallableStatement
477       * @see ResultSet
478       * @since 1.4
479       */
480      CallableStatement prepareCall(String sql, int resultSetType, int
481          resultSetConcurrency, int resultSetHoldability) throws SQLException;
482    
483      /**
484       * @since 1.4
485       */
486      PreparedStatement prepareStatement(String sql, int autoGeneratedKeys)
487          throws SQLException;
488    
489      /**
490       * @since 1.4
491       */
492      PreparedStatement prepareStatement(String sql, int[] columnIndexes)
493          throws SQLException;
494    
495      /**
496       * @since 1.4
497       */
498      PreparedStatement prepareStatement(String sql, String[] columnNames)
499          throws SQLException;
500    }