001/* Connection.java -- Manage a database connection.
002   Copyright (C) 1999, 2000, 2002, 2006 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package java.sql;
040
041import 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 */
048public 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}