1QSqlDriver(3qt) QSqlDriver(3qt)
2
6 QSqlDriver - Abstract base class for accessing SQL databases
7
9 #include <qsqldriver.h>
10 Inherits QObject.
12 Public Members
14 enum DriverFeature { Transactions, QuerySize, BLOB, Unicode,
15 PreparedQueries, NamedPlaceholders, PositionalPlaceholders }
16 QSqlDriver ( QObject * parent = 0, const char * name = 0 )
17 ~QSqlDriver ()
18 bool isOpen () const
19 bool isOpenError () const
20 virtual bool beginTransaction ()
21 virtual bool commitTransaction ()
22 virtual bool rollbackTransaction ()
23 virtual QStringList tables ( const QString & tableType ) const
24 virtual QSqlIndex primaryIndex ( const QString & tableName ) const
25 virtual QSqlRecord record ( const QString & tableName ) const
26 virtual QSqlRecord record ( const QSqlQuery & query ) const
27 virtual QSqlRecordInfo recordInfo ( const QString & tablename ) const
28 virtual QSqlRecordInfo recordInfo ( const QSqlQuery & query ) const
29 virtual QString nullText () const
30 virtual QString formatValue ( const QSqlField * field, bool trimStrings
31 = FALSE ) const
32 QSqlError lastError () const
33 virtual bool hasFeature ( DriverFeature f ) const = 0
34 virtual bool open ( const QString & db, const QString & user =
35 QString::null, const QString & password = QString::null, const
36 QString & host = QString::null, int port = -1 ) = 0
37 virtual void close () = 0
38 virtual QSqlQuery createQuery () const = 0
39 bool open ( const QString & db, const QString & user, const QString &
40 password, const QString & host, int port, const QString & connOpts
41 )
42 Protected Members
44 virtual void setOpen ( bool o )
45 virtual void setOpenError ( bool e )
46 virtual void setLastError ( const QSqlError & e )
47
49 The QSqlDriver class is an abstract base class for accessing SQL
50 databases.
51 This class should not be used directly. Use QSqlDatabase instead.
53 See also Database Classes.
55 Member Type Documentation
58 This enum contains a list of features a driver may support. Use
59 hasFeature() to query whether a feature is supported or not.
60 QSqlDriver::Transactions - whether the driver supports SQL transactions
62 QSqlDriver::QuerySize - whether the database is capable of reporting
64 the size of a query. Note that some databases do not support returning
65 the size (i.e. number of rows returned) of a query, in which case
66 QSqlQuery::size() will return -1
67 QSqlDriver::BLOB - whether the driver supports Binary Large Object
69 fields
70 QSqlDriver::Unicode - whether the driver supports Unicode strings if
72 the database server does
73 QSqlDriver::PreparedQueries - whether the driver supports prepared
75 query execution
76 QSqlDriver::NamedPlaceholders - whether the driver supports usage of
78 named placeholders
79 QSqlDriver::PositionalPlaceholders - whether the driver supports usage
81 of positional placeholders
82 More information about supported features can be found in the Qt SQL
84 driver documentation.
85 See also hasFeature().
87
90 Default constructor. Creates a new driver with parent parent, called
91 name.
92
94 Destroys the object and frees any allocated resources.
95
97 Protected function which derived classes can reimplement to begin a
98 transaction. If successful, return TRUE, otherwise return FALSE. The
99 default implementation returns FALSE.
100 See also commitTransaction() and rollbackTransaction().
102
104 Derived classes must reimplement this abstract virtual function in
105 order to close the database connection. Return TRUE on success, FALSE
106 on failure.
107 See also setOpen().
109
111 Protected function which derived classes can reimplement to commit a
112 transaction. If successful, return TRUE, otherwise return FALSE. The
113 default implementation returns FALSE.
114 See also beginTransaction() and rollbackTransaction().
116
118 Creates an empty SQL result on the database. Derived classes must
119 reimplement this function and return a QSqlQuery object appropriate for
120 their database to the caller.
121
123 FALSE ) const [virtual]
124 Returns a string representation of the field value for the database.
125 This is used, for example, when constructing INSERT and UPDATE
126 statements.
127 The default implementation returns the value formatted as a string
129 according to the following rules:
130 If field is NULL, nullText() is returned.
132 If field is character data, the value is returned enclosed in single
134 quotation marks, which is appropriate for many SQL databases. Any
135 embedded single-quote characters are escaped (replaced with two single-
136 quote characters). If trimStrings is TRUE (the default is FALSE), all
137 trailing whitespace is trimmed from the field.
138 If field is date/time data, the value is formatted in ISO format and
140 enclosed in single quotation marks. If the date/time data is invalid,
141 nullText() is returned.
142 If field is bytearray data, and the driver can edit binary fields, the
144 value is formatted as a hexadecimal string.
145 For any other field type toString() will be called on its value and the
147 result returned.
148 See also QVariant::toString().
150
152 Returns TRUE if the driver supports feature f; otherwise returns FALSE.
153 Note that some databases need to be open() before this can be
155 determined.
156 See also DriverFeature.
158
160 Returns TRUE if the database connection is open; otherwise returns
161 FALSE.
162
164 Returns TRUE if the there was an error opening the database connection;
165 otherwise returns FALSE.
166
168 Returns a QSqlError object which contains information about the last
169 error that occurred on the database.
170
172 Returns a string representation of the NULL value for the database.
173 This is used, for example, when constructing INSERT and UPDATE
174 statements. The default implementation returns the string" NULL".
175
177 QString::null, const QString & password = QString::null, const QString
178 & host = QString::null, int port = -1 ) [pure virtual]
179 Derived classes must reimplement this abstract virtual function in
180 order to open a database connection on database db, using user name
181 user, password password, host host and port port.
182 The function must return TRUE on success and FALSE on failure.
184 See also setOpen().
186
188 QString & password, const QString & host, int port, const QString &
189 connOpts )
190 This is an overloaded member function, provided for convenience. It
191 behaves essentially like the above function.
192 Open a database connection on database db, using user name user,
194 password password, host host, port port and connection options
195 connOpts.
196 Returns TRUE on success and FALSE on failure.
198 See also setOpen().
200
202 [virtual]
203 Returns the primary index for table tableName. Returns an empty
204 QSqlIndex if the table doesn't have a primary index. The default
205 implementation returns an empty index.
206
208 Returns a QSqlRecord populated with the names of the fields in table
209 tableName. If no such table exists, an empty record is returned. The
210 default implementation returns an empty record.
211
213 This is an overloaded member function, provided for convenience. It
214 behaves essentially like the above function.
215 Returns a QSqlRecord populated with the names of the fields in the SQL
217 query. The default implementation returns an empty record.
218
220 [virtual]
221 Returns a QSqlRecordInfo object with meta data about the table
222 tablename.
223
225 [virtual]
226 This is an overloaded member function, provided for convenience. It
227 behaves essentially like the above function.
228 Returns a QSqlRecordInfo object with meta data for the QSqlQuery query.
230 Note that this overloaded function may return less information than the
231 recordInfo() function which takes the name of a table as parameter.
232
234 Protected function which derived classes can reimplement to rollback a
235 transaction. If successful, return TRUE, otherwise return FALSE. The
236 default implementation returns FALSE.
237 See also beginTransaction() and commitTransaction().
239
241 Protected function which allows derived classes to set the value of the
242 last error, e, that occurred on the database.
243 See also lastError().
245
247 Protected function which sets the open state of the database to o.
248 Derived classes can use this function to report the status of open().
249 See also open() and setOpenError().
251
253 Protected function which sets the open error state of the database to
254 e. Derived classes can use this function to report the status of
255 open(). Note that if e is TRUE the open state of the database is set to
256 closed (i.e. isOpen() returns FALSE).
257 See also open().
259
261 Returns a list of tables in the database. The default implementation
262 returns an empty list.
263 The tableType argument describes what types of tables should be
265 returned. Due to binary compatibility, the string contains the value of
266 the enum QSql::TableTypes as text. An empty string should be treated as
267 QSql::Tables for downward compatibility.
268 See also QSql::TableType.
270
273 http://doc.trolltech.com/qsqldriver.html
274 http://www.trolltech.com/faq/tech.html
275
277 Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
278 license file included in the distribution for a complete license
279 statement.
280
282 Generated automatically from the source code.
283
285 If you find a bug in Qt, please report it as described in
286 http://doc.trolltech.com/bughowto.html. Good bug reports help us to
287 help you. Thank you.
288 The definitive Qt documentation is provided in HTML format; it is
290 located at $QTDIR/doc/html and can be read using Qt Assistant or with a
291 web browser. This man page is provided as a convenience for those users
292 who prefer man pages, although this format is not officially supported
293 by Trolltech.
294 If you find errors in this manual page, please report them to qt-
296 bugs@trolltech.com. Please include the name of the manual page
297 (qsqldriver.3qt) and the Qt version (3.3.8).
298Trolltech AS 2 February 2007 QSqlDriver(3qt)