summaryrefslogtreecommitdiffstats
path: root/src/sql/qsqlquery.cpp
blob: 829e469479115c1919dd9fa6e1a237e3de43f5aa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
/****************************************************************************
**
** Implementation of TQSqlQuery class
**
** Created : 2000-11-03
**
** Copyright (C) 2000-2008 Trolltech ASA.  All rights reserved.
**
** This file is part of the sql module of the TQt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free TQt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** This file may be used under the terms of the Q Public License as
** defined by Trolltech ASA and appearing in the file LICENSE.TQPL
** included in the packaging of this file.  Licensees holding valid TQt
** Commercial licenses may use this file in accordance with the TQt
** Commercial License Agreement provided with the Software.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/

#include "ntqsqlquery.h"

#ifndef TQT_NO_SQL

//#define QT_DEBUG_SQL

#include "ntqsqlresult.h"
#include "ntqsqldriver.h"
#include "ntqsqldatabase.h"
#include "ntqsql.h"
#include "ntqregexp.h"
#include "private/qsqlextension_p.h"


/*!
\internal
*/
TQSqlResultShared::TQSqlResultShared( TQSqlResult* result ): sqlResult(result)
{
    if ( result )
	connect( result->driver(), SIGNAL(destroyed()), this, SLOT(slotResultDestroyed()) );
}

/*!
\internal
*/
TQSqlResultShared::~TQSqlResultShared()
{
    delete sqlResult;
}

/*!
\internal

In case a plugin gets unloaded the pointer to the sqlResult gets invalid
*/
void TQSqlResultShared::slotResultDestroyed()
{
    delete sqlResult;
    sqlResult = 0;
}

/*!
    \class TQSqlQuery ntqsqlquery.h
    \brief The TQSqlQuery class provides a means of executing and
    manipulating SQL statements.

    \ingroup database
    \mainclass
    \module sql

    TQSqlQuery encapsulates the functionality involved in creating,
    navigating and retrieving data from SQL queries which are executed
    on a \l TQSqlDatabase. It can be used to execute DML (data
    manipulation language) statements, e.g. \c SELECT, \c INSERT, \c
    UPDATE and \c DELETE, and also DDL (data definition language)
    statements, e.g. \c{CREATE TABLE}. It can also be used to
    execute database-specific commands which are not standard SQL
    (e.g. \c{SET DATESTYLE=ISO} for PostgreSQL).

    Successfully executed SQL statements set the query's state to
    active (isActive() returns TRUE); otherwise the query's state is
    set to inactive. In either case, when executing a new SQL
    statement, the query is positioned on an invalid record; an active
    query must be navigated to a valid record (so that isValid()
    returns TRUE) before values can be retrieved.

    Navigating records is performed with the following functions:

    \list
    \i \c next()
    \i \c prev()
    \i \c first()
    \i \c last()
    \i \c \link TQSqlQuery::seek() seek\endlink(int)
    \endlist

    These functions allow the programmer to move forward, backward or
    arbitrarily through the records returned by the query. If you only
    need to move forward through the results, e.g. using next() or
    using seek() with a positive offset, you can use setForwardOnly()
    and save a significant amount of memory overhead. Once an active
    query is positioned on a valid record, data can be retrieved using
    value(). All data is transferred from the SQL backend using
    TQVariants.

    For example:

    \code
    TQSqlQuery query( "SELECT name FROM customer" );
    while ( query.next() ) {
	TQString name = query.value(0).toString();
	doSomething( name );
    }
    \endcode

    To access the data returned by a query, use the value() method.
    Each field in the data returned by a SELECT statement is accessed
    by passing the field's position in the statement, starting from 0.
    Information about the fields can be obtained via TQSqlDatabase::record().
    For the sake of efficiency there are no functions to access a field
    by name. (The \l TQSqlCursor class provides a higher-level interface
    with field access by name and automatic SQL generation.)

    TQSqlQuery supports prepared query execution and the binding of
    parameter values to placeholders. Some databases don't support
    these features, so for them TQt emulates the required
    functionality. For example, the Oracle and ODBC drivers have
    proper prepared query support, and TQt makes use of it; but for
    databases that don't have this support, TQt implements the feature
    itself, e.g. by replacing placeholders with actual values when a
    query is executed. The exception is positional binding using named
    placeholders, which requires that the database supports prepared
    queries.

    Oracle databases identify placeholders by using a colon-name
    syntax, e.g \c{:name}. ODBC simply uses \c ? characters. TQt
    supports both syntaxes (although you can't mix them in the same
    query).

    Below we present the same example using each of the four different
    binding approaches.

    <b>Named binding using named placeholders</b>
    \code
    TQSqlQuery query;
    query.prepare( "INSERT INTO atable (id, forename, surname) "
	           "VALUES (:id, :forename, :surname)" );
    query.bindValue( ":id", 1001 );
    query.bindValue( ":forename", "Bart" );
    query.bindValue( ":surname", "Simpson" );
    query.exec();
    \endcode

    <b>Positional binding using named placeholders</b>
    \code
    TQSqlQuery query;
    query.prepare( "INSERT INTO atable (id, forename, surname) "
		   "VALUES (:id, :forename, :surname)" );
    query.bindValue( 0, 1001 );
    query.bindValue( 1, "Bart" );
    query.bindValue( 2, "Simpson" );
    query.exec();
    \endcode
    <b>Note:</b> Using positional binding with named placeholders will
    only work if the database supports prepared queries. This can be
    checked with TQSqlDriver::hasFeature() using TQSqlDriver::PreparedQueries
    as argument for driver feature.

    <b>Binding values using positional placeholders #1</b>
    \code
    TQSqlQuery query;
    query.prepare( "INSERT INTO atable (id, forename, surname) "
		   "VALUES (?, ?, ?)" );
    query.bindValue( 0, 1001 );
    query.bindValue( 1, "Bart" );
    query.bindValue( 2, "Simpson" );
    query.exec();
    \endcode

    <b>Binding values using positional placeholders #2</b>
    \code
    query.prepare( "INSERT INTO atable (id, forename, surname) "
		   "VALUES (?, ?, ?)" );
    query.addBindValue( 1001 );
    query.addBindValue( "Bart" );
    query.addBindValue( "Simpson" );
    query.exec();
    \endcode

    <b>Binding values to a stored procedure</b>
    This code calls a stored procedure called \c AsciiToInt(), passing
    it a character through its in parameter, and taking its result in
    the out parameter.
    \code
    TQSqlQuery query;
    query.prepare( "call AsciiToInt(?, ?)" );
    query.bindValue( 0, "A" );
    query.bindValue( 1, 0, TQSql::Out );
    query.exec();
    int i = query.boundValue( 1 ).toInt(); // i is 65.
    \endcode

    \sa TQSqlDatabase TQSqlCursor TQVariant
*/

/*!
    Creates a TQSqlQuery object which uses the TQSqlResult \a r to
    communicate with a database.
*/

TQSqlQuery::TQSqlQuery( TQSqlResult * r )
{
    d = new TQSqlResultShared( r );
}

/*!
    Destroys the object and frees any allocated resources.
*/

TQSqlQuery::~TQSqlQuery()
{
    if (d->deref()) {
	delete d;
    }
}

/*!
    Constructs a copy of \a other.
*/

TQSqlQuery::TQSqlQuery( const TQSqlQuery& other )
    : d(other.d)
{
    d->ref();
}

/*!
    Creates a TQSqlQuery object using the SQL \a query and the database
    \a db. If \a db is 0, (the default), the application's default
    database is used. If \a query is not a null string, it will be
    executed.

    \sa TQSqlDatabase
*/
TQSqlQuery::TQSqlQuery( const TQString& query, TQSqlDatabase* db )
{
    init( query, db );
}

/*!
    Creates a TQSqlQuery object using the database \a db. If \a db is
    0, the application's default database is used.

    \sa TQSqlDatabase
*/

TQSqlQuery::TQSqlQuery( TQSqlDatabase* db )
{
    init( TQString::null, db );
}

/*! \internal
*/

void TQSqlQuery::init( const TQString& query, TQSqlDatabase* db )
{
    d = new TQSqlResultShared( 0 );
    TQSqlDatabase* database = db;
    if ( !database )
	database = TQSqlDatabase::database( TQSqlDatabase::defaultConnection, FALSE );
    if ( database )
	*this = database->driver()->createQuery();
    if ( !query.isNull() )
	exec( query );
}

/*!
    Assigns \a other to the query.
*/

TQSqlQuery& TQSqlQuery::operator=( const TQSqlQuery& other )
{
    other.d->ref();
    deref();
    d = other.d;
    return *this;
}

/*!
    Returns TRUE if the query is active and positioned on a valid
    record and the \a field is NULL; otherwise returns FALSE. Note
    that for some drivers isNull() will not return accurate
    information until after an attempt is made to retrieve data.

    \sa isActive() isValid() value()
*/

bool TQSqlQuery::isNull( int field ) const
{
    if ( !d->sqlResult )
	return FALSE;
    if ( d->sqlResult->isActive() && d->sqlResult->isValid() )
	return d->sqlResult->isNull( field );
    return FALSE;
}

/*!
    Executes the SQL in \a query. Returns TRUE and sets the query
    state to active if the query was successful; otherwise returns
    FALSE and sets the query state to inactive. The \a query string
    must use syntax appropriate for the SQL database being queried,
    for example, standard SQL.

    After the query is executed, the query is positioned on an \e
    invalid record, and must be navigated to a valid record before
    data values can be retrieved, e.g. using next().

    Note that the last error for this query is reset when exec() is
    called.

    \sa isActive() isValid() next() prev() first() last() seek()
*/

bool TQSqlQuery::exec ( const TQString& query )
{
    if ( !d->sqlResult )
	return FALSE;
    if ( d->sqlResult->extension() && driver()->hasFeature( TQSqlDriver::PreparedQueries ) )
	d->sqlResult->extension()->clear();
    d->sqlResult->setActive( FALSE );
    d->sqlResult->setLastError( TQSqlError() );
    d->sqlResult->setAt( TQSql::BeforeFirst );
    if ( !driver() ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::exec: no driver" );
#endif
	return FALSE;
    }
    if ( d->count > 1 )
	*this = driver()->createQuery();
    d->sqlResult->setQuery( query.stripWhiteSpace() );
    d->executedQuery = d->sqlResult->lastQuery();
    if ( !driver()->isOpen() || driver()->isOpenError() ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::exec: database not open" );
#endif
	return FALSE;
    }
    if ( query.isNull() || query.length() == 0 ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::exec: empty query" );
#endif
	return FALSE;
    }
#ifdef QT_DEBUG_SQL
    tqDebug( "\n TQSqlQuery: " + query );
#endif
    return d->sqlResult->reset( query );
}

/*!
    Returns the value of the \a{i}-th field in the query (zero based).

    The fields are numbered from left to right using the text of the
    \c SELECT statement, e.g. in \c{SELECT forename, surname FROM people},
    field 0 is \c forename and field 1 is \c surname. Using \c{SELECT *}
    is not recommended because the order of the fields in the query is
    undefined.

    An invalid TQVariant is returned if field \a i does not exist, if
    the query is inactive, or if the query is positioned on an invalid
    record.

    \sa prev() next() first() last() seek() isActive() isValid()
*/

TQVariant TQSqlQuery::value( int i ) const
{
    if ( !d->sqlResult )
	return TQVariant();
    if ( isActive() && isValid() && ( i > TQSql::BeforeFirst ) ) {
	return d->sqlResult->data( i );
    } else {
#ifdef QT_CHECK_RANGE
	tqWarning( "TQSqlQuery::value: not positioned on a valid record" );
#endif
    }
    return TQVariant();
}

/*!
    Returns the current internal position of the query. The first
    record is at position zero. If the position is invalid, a
    TQSql::Location will be returned indicating the invalid position.

    \sa prev() next() first() last() seek() isActive() isValid()
*/

int TQSqlQuery::at() const
{
    if ( !d->sqlResult )
	return TQSql::BeforeFirst;
    return d->sqlResult->at();
}

/*!
    Returns the text of the current query being used, or TQString::null
    if there is no current query text.

    \sa executedQuery()
*/

TQString TQSqlQuery::lastQuery() const
{
    if ( !d->sqlResult )
	return TQString::null;
    return d->sqlResult->lastQuery();
}

/*!
    Returns the database driver associated with the query.
*/

const TQSqlDriver* TQSqlQuery::driver() const
{
    if ( !d->sqlResult )
	return 0;
    return d->sqlResult->driver();
}

/*!
    Returns the result associated with the query.
*/

const TQSqlResult* TQSqlQuery::result() const
{
    return d->sqlResult;
}

/*!
    Retrieves the record at position (offset) \a i, if available, and
    positions the query on the retrieved record. The first record is
    at position 0. Note that the query must be in an active state and
    isSelect() must return TRUE before calling this function.

    If \a relative is FALSE (the default), the following rules apply:

    \list
    \i If \a i is negative, the result is positioned before the
    first record and FALSE is returned.
    \i Otherwise, an attempt is made to move to the record at position
    \a i. If the record at position \a i could not be retrieved, the
    result is positioned after the last record and FALSE is returned. If
    the record is successfully retrieved, TRUE is returned.
    \endlist

    If \a relative is TRUE, the following rules apply:

    \list
    \i If the result is currently positioned before the first
    record or on the first record, and \a i is negative, there is no
    change, and FALSE is returned.
    \i If the result is currently located after the last record, and
    \a i is positive, there is no change, and FALSE is returned.
    \i If the result is currently located somewhere in the middle,
    and the relative offset \a i moves the result below zero, the
    result is positioned before the first record and FALSE is
    returned.
    \i Otherwise, an attempt is made to move to the record \a i
    records ahead of the current record (or \a i records behind the
    current record if \a i is negative). If the record at offset \a i
    could not be retrieved, the result is positioned after the last
    record if \a i >= 0, (or before the first record if \a i is
    negative), and FALSE is returned. If the record is successfully
    retrieved, TRUE is returned.
    \endlist

    \sa next() prev() first() last() at() isActive() isValid()
*/
bool TQSqlQuery::seek( int i, bool relative )
{
    if ( !isSelect() || !isActive() )
	return FALSE;
    beforeSeek();
    checkDetach();
    int actualIdx;
    if ( !relative ) { // arbitrary seek
	if ( i < 0 ) {
	    d->sqlResult->setAt( TQSql::BeforeFirst );
	    afterSeek();
	    return FALSE;
	}
	actualIdx = i;
    } else {
	switch ( at() ) { // relative seek
	case TQSql::BeforeFirst:
	    if ( i > 0 )
		actualIdx = i;
	    else {
		afterSeek();
		return FALSE;
	    }
	    break;
	case TQSql::AfterLast:
	    if ( i < 0 ) {
		d->sqlResult->fetchLast();
		actualIdx = at() + i;
	    } else {
		afterSeek();
		return FALSE;
	    }
	    break;
	default:
	    if ( ( at() + i ) < 0  ) {
		d->sqlResult->setAt( TQSql::BeforeFirst );
		afterSeek();
		return FALSE;
	    }
	    actualIdx = at() + i;
	    break;
	}
    }
    // let drivers optimize
    if ( isForwardOnly() && actualIdx < at() ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::seek: cannot seek backwards in a forward only query" );
#endif
	afterSeek();
	return FALSE;
    }
    if ( actualIdx == ( at() + 1 ) && at() != TQSql::BeforeFirst ) {
	if ( !d->sqlResult->fetchNext() ) {
	    d->sqlResult->setAt( TQSql::AfterLast );
	    afterSeek();
	    return FALSE;
	}
	afterSeek();
	return TRUE;
    }
    if ( actualIdx == ( at() - 1 ) ) {
	if ( !d->sqlResult->fetchPrev() ) {
	    d->sqlResult->setAt( TQSql::BeforeFirst );
	    afterSeek();
	    return FALSE;
	}
	afterSeek();
	return TRUE;
    }
    if ( !d->sqlResult->fetch( actualIdx ) ) {
	d->sqlResult->setAt( TQSql::AfterLast );
	afterSeek();
	return FALSE;
    }
    afterSeek();
    return TRUE;
}

/*!
    Retrieves the next record in the result, if available, and
    positions the query on the retrieved record. Note that the result
    must be in an active state and isSelect() must return TRUE before
    calling this function or it will do nothing and return FALSE.

    The following rules apply:

    \list
    \i If the result is currently located before the first
    record, e.g. immediately after a query is executed, an attempt is
    made to retrieve the first record.

    \i If the result is currently located after the last record,
    there is no change and FALSE is returned.

    \i If the result is located somewhere in the middle, an attempt
    is made to retrieve the next record.
    \endlist

    If the record could not be retrieved, the result is positioned after
    the last record and FALSE is returned. If the record is successfully
    retrieved, TRUE is returned.

    \sa prev() first() last() seek() at() isActive() isValid()
*/

bool TQSqlQuery::next()
{
    if ( !isSelect() || !isActive() )
	return FALSE;
    beforeSeek();
    checkDetach();
    bool b = FALSE;
    switch ( at() ) {
    case TQSql::BeforeFirst:
	b = d->sqlResult->fetchFirst();
	afterSeek();
	return b;
    case TQSql::AfterLast:
	afterSeek();
	return FALSE;
    default:
	if ( !d->sqlResult->fetchNext() ) {
	    d->sqlResult->setAt( TQSql::AfterLast );
	    afterSeek();
	    return FALSE;
	}
	afterSeek();
	return TRUE;
    }
}

/*!
    Retrieves the previous record in the result, if available, and
    positions the query on the retrieved record. Note that the result
    must be in an active state and isSelect() must return TRUE before
    calling this function or it will do nothing and return FALSE.

    The following rules apply:

    \list
    \i If the result is currently located before the first record,
    there is no change and FALSE is returned.

    \i If the result is currently located after the last record, an
    attempt is made to retrieve the last record.

    \i If the result is somewhere in the middle, an attempt is made
    to retrieve the previous record.
    \endlist

    If the record could not be retrieved, the result is positioned
    before the first record and FALSE is returned. If the record is
    successfully retrieved, TRUE is returned.

    \sa next() first() last() seek() at() isActive() isValid()
*/

bool TQSqlQuery::prev()
{
    if ( !isSelect() || !isActive() )
	return FALSE;
    if ( isForwardOnly() ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::seek: cannot seek backwards in a forward only query" );
#endif
	return FALSE;
    }

    beforeSeek();
    checkDetach();
    bool b = FALSE;
    switch ( at() ) {
    case TQSql::BeforeFirst:
	afterSeek();
	return FALSE;
    case TQSql::AfterLast:
	b = d->sqlResult->fetchLast();
	afterSeek();
	return b;
    default:
	if ( !d->sqlResult->fetchPrev() ) {
	    d->sqlResult->setAt( TQSql::BeforeFirst );
	    afterSeek();
	    return FALSE;
	}
	afterSeek();
	return TRUE;
    }
}

/*!
    Retrieves the first record in the result, if available, and
    positions the query on the retrieved record. Note that the result
    must be in an active state and isSelect() must return TRUE before
    calling this function or it will do nothing and return FALSE.
    Returns TRUE if successful. If unsuccessful the query position is
    set to an invalid position and FALSE is returned.

    \sa next() prev() last() seek() at() isActive() isValid()
*/

bool TQSqlQuery::first()
{
    if ( !isSelect() || !isActive() )
	return FALSE;
    if ( isForwardOnly() && at() > TQSql::BeforeFirst ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::seek: cannot seek backwards in a forward only query" );
#endif
	return FALSE;
    }
    beforeSeek();
    checkDetach();
    bool b = FALSE;
    b = d->sqlResult->fetchFirst();
    afterSeek();
    return b;
}

/*!
    Retrieves the last record in the result, if available, and
    positions the query on the retrieved record. Note that the result
    must be in an active state and isSelect() must return TRUE before
    calling this function or it will do nothing and return FALSE.
    Returns TRUE if successful. If unsuccessful the query position is
    set to an invalid position and FALSE is returned.

    \sa next() prev() first() seek() at() isActive() isValid()
*/

bool TQSqlQuery::last()
{
    if ( !isSelect() || !isActive() )
	return FALSE;
    beforeSeek();
    checkDetach();
    bool b = FALSE;
    b = d->sqlResult->fetchLast();
    afterSeek();
    return b;
}

/*!
    Returns the size of the result, (number of rows returned), or -1
    if the size cannot be determined or if the database does not
    support reporting information about query sizes. Note that for
    non-\c SELECT statements (isSelect() returns FALSE), size() will
    return -1. If the query is not active (isActive() returns FALSE),
    -1 is returned.

    To determine the number of rows affected by a non-SELECT
    statement, use numRowsAffected().

    \sa isActive() numRowsAffected() TQSqlDriver::hasFeature()
*/
int TQSqlQuery::size() const
{
    if ( !d->sqlResult )
	return -1;
    if ( isActive() && d->sqlResult->driver()->hasFeature( TQSqlDriver::QuerySize ) )
	return d->sqlResult->size();
    return -1;
}

/*!
    Returns the number of rows affected by the result's SQL statement,
    or -1 if it cannot be determined. Note that for \c SELECT
    statements, the value is undefined; see size() instead. If the
    query is not active (isActive() returns FALSE), -1 is returned.

    \sa size() TQSqlDriver::hasFeature()
*/

int TQSqlQuery::numRowsAffected() const
{
    if ( !d->sqlResult )
	return -1;
    if ( isActive() )
	return d->sqlResult->numRowsAffected();
    return -1;
}

/*!
    Returns error information about the last error (if any) that
    occurred.

    \sa TQSqlError
*/

TQSqlError TQSqlQuery::lastError() const
{
    if ( !d->sqlResult )
	return TQSqlError();
    return d->sqlResult->lastError();
}

/*!
    Returns TRUE if the query is currently positioned on a valid
    record; otherwise returns FALSE.
*/

bool TQSqlQuery::isValid() const
{
    if ( !d->sqlResult )
	return FALSE;
    return d->sqlResult->isValid();
}

/*!
    Returns TRUE if the query is currently active; otherwise returns
    FALSE.
*/

bool TQSqlQuery::isActive() const
{
    if ( !d->sqlResult )
	return FALSE;
    return d->sqlResult->isActive();
}

/*!
    Returns TRUE if the current query is a \c SELECT statement;
    otherwise returns FALSE.
*/

bool TQSqlQuery::isSelect() const
{
    if ( !d->sqlResult )
	return FALSE;
    return d->sqlResult->isSelect();
}

/*!
    Returns TRUE if you can only scroll \e forward through a result
    set; otherwise returns FALSE.

    \sa setForwardOnly()
*/
bool TQSqlQuery::isForwardOnly() const
{
    if ( !d->sqlResult )
	return FALSE;
    return d->sqlResult->isForwardOnly();
}

/*!
    Sets forward only mode to \a forward. If forward is TRUE only
    next(), and seek() with positive values, are allowed for
    navigating the results. Forward only mode needs far less memory
    since results do not need to be cached.

    Forward only mode is off by default.

    Forward only mode cannot be used with data aware widgets like
    TQDataTable, since they must to be able to scroll backward as well
    as forward.

    \sa isForwardOnly(), next(), seek()
*/
void TQSqlQuery::setForwardOnly( bool forward )
{
    if ( d->sqlResult )
	d->sqlResult->setForwardOnly( forward );
}

/*!
  \internal
*/

void TQSqlQuery::deref()
{
    if ( d->deref() ) {
	delete d;
	d = 0;
    }
}

/*!
  \internal
*/

bool TQSqlQuery::checkDetach()
{
    if ( d->count > 1 && d->sqlResult ) {
	TQString sql = d->sqlResult->lastQuery();
	*this = driver()->createQuery();
	exec( sql );
	return TRUE;
    }
    return FALSE;
}


/*!
    Protected virtual function called before the internal record
    pointer is moved to a new record. The default implementation does
    nothing.
*/

void TQSqlQuery::beforeSeek()
{

}


/*!
    Protected virtual function called after the internal record
    pointer is moved to a new record. The default implementation does
    nothing.
*/

void TQSqlQuery::afterSeek()
{

}

// XXX: Hack to keep BCI - remove in 4.0. TQSqlExtension should be
// removed, and the prepare(), exec() etc. fu's should be
// made virtual members of TQSqlQuery/TQSqlResult

/*!
    Prepares the SQL query \a query for execution. The query may
    contain placeholders for binding values. Both Oracle style
    colon-name (e.g. \c{:surname}), and ODBC style (e.g. \c{?})
    placeholders are supported; but they cannot be mixed in the same
    query. See the \link #details Description\endlink for examples.

    \sa exec(), bindValue(), addBindValue()
*/
bool TQSqlQuery::prepare( const TQString& query )
{
    if ( !d->sqlResult || !d->sqlResult->extension() )
	return FALSE;
    d->sqlResult->setActive( FALSE );
    d->sqlResult->setLastError( TQSqlError() );
    d->sqlResult->setAt( TQSql::BeforeFirst );
    d->sqlResult->extension()->clear();
    if ( !driver() ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::prepare: no driver" );
#endif
	return FALSE;
    }
    if ( d->count > 1 )
	*this = driver()->createQuery();
    d->sqlResult->setQuery( query.stripWhiteSpace() );
    if ( !driver()->isOpen() || driver()->isOpenError() ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::prepare: database not open" );
#endif
	return FALSE;
    }
    if ( query.isNull() || query.length() == 0 ) {
#ifdef QT_CHECK_RANGE
	tqWarning("TQSqlQuery::prepare: empty query" );
#endif
	return FALSE;
    }
#ifdef QT_DEBUG_SQL
    tqDebug( "\n TQSqlQuery: " + query );
#endif
    TQString q = query;
    TQRegExp rx(TQString::fromLatin1("'[^']*'|:([a-zA-Z0-9_]+)"));
    if ( driver()->hasFeature( TQSqlDriver::PreparedQueries ) ) {
	// below we substitute Oracle placeholders with ODBC ones and
	// vice versa to make this db independent
	int i = 0, cnt = 0;
	if ( driver()->hasFeature( TQSqlDriver::NamedPlaceholders ) ) {
	    TQRegExp rx(TQString::fromLatin1("'[^']*'|\\?"));
	    while ( (i = rx.search( q, i )) != -1 ) {
		if ( rx.cap(0) == "?" ) {
		    q = q.replace( i, 1, ":f" + TQString::number(cnt) );
		    cnt++;
		}
		i += rx.matchedLength();
	    }
	} else if ( driver()->hasFeature( TQSqlDriver::PositionalPlaceholders ) ) {
	    while ( (i = rx.search( q, i )) != -1 ) {
		if ( rx.cap(1).isEmpty() ) {
		    i += rx.matchedLength();
		} else {
		    // record the index of the placeholder - needed
		    // for emulating named bindings with ODBC
		    d->sqlResult->extension()->index[ cnt ]= rx.cap(0);
		    q = q.replace( i, rx.matchedLength(), "?" );
		    i++;
		    cnt++;
		}
	    }
	}
	d->executedQuery = q;
	return d->sqlResult->extension()->prepare( q );
    } else {
	int i = 0;
	while ( (i = rx.search( q, i )) != -1 ) {
	    if ( !rx.cap(1).isEmpty() )
		d->sqlResult->extension()->holders.append( Holder( rx.cap(0), i ) );
	    i += rx.matchedLength();
	}
	return TRUE; // fake prepares should always succeed
    }
}

/*!
    \overload

    Executes a previously prepared SQL query. Returns TRUE if the
    query executed successfully; otherwise returns FALSE.

    \sa prepare(), bindValue(), addBindValue()
*/
bool TQSqlQuery::exec()
{
    bool ret;
    if ( !d->sqlResult || !d->sqlResult->extension() )
	return FALSE;
    if ( driver()->hasFeature( TQSqlDriver::PreparedQueries ) ) {
	ret = d->sqlResult->extension()->exec();
    } else {
	// fake preparation - just replace the placeholders..
	TQString query = d->sqlResult->lastQuery();
	if ( d->sqlResult->extension()->bindMethod() == TQSqlExtension::BindByName ) {
	    int i;
	    TQVariant val;
	    TQString holder;
	    for ( i = (int)d->sqlResult->extension()->holders.count() - 1; i >= 0; --i ) {
		holder = d->sqlResult->extension()->holders[ (uint)i ].holderName;
		val = d->sqlResult->extension()->values[ holder ].value;
		TQSqlField f( "", val.type() );
		if ( val.isNull() )
		    f.setNull();
		else
		    f.setValue( val );
		query = query.replace( (uint)d->sqlResult->extension()->holders[ (uint)i ].holderPos,
			holder.length(), driver()->formatValue( &f ) );
	    }
	} else {
	    TQMap<int, TQString>::ConstIterator it;
	    TQString val;
	    int i = 0;
	    for ( it = d->sqlResult->extension()->index.begin();
		  it != d->sqlResult->extension()->index.end(); ++it ) {
		i = query.find( '?', i );
		if ( i > -1 ) {
		    TQSqlField f( "", d->sqlResult->extension()->values[ it.data() ].value.type() );
		    if ( d->sqlResult->extension()->values[ it.data() ].value.isNull() )
			f.setNull();
		    else
			f.setValue( d->sqlResult->extension()->values[ it.data() ].value );
		    val = driver()->formatValue( &f );
		    query = query.replace( i, 1, driver()->formatValue( &f ) );
		    i += val.length();
		}
	    }
	}
	// have to retain the original query w/placeholders..
	TQString orig = d->sqlResult->lastQuery();
	ret = exec( query );
	d->executedQuery = query;
	d->sqlResult->setQuery( orig );
    }
    d->sqlResult->extension()->resetBindCount();
    return ret;
}

/*!
    Set the placeholder \a placeholder to be bound to value \a val in
    the prepared statement. Note that the placeholder mark (e.g \c{:})
    must be included when specifying the placeholder name. If \a type
    is \c TQSql::Out or \c TQSql::InOut, the placeholder will be
    overwritten with data from the database after the exec() call.

    \sa addBindValue(), prepare(), exec()
*/
void TQSqlQuery::bindValue( const TQString& placeholder, const TQVariant& val, TQSql::ParameterType type )
{
    if ( !d->sqlResult || !d->sqlResult->extension() )
	return;
    d->sqlResult->extension()->bindValue( placeholder, val, type );
}

/*!
    \overload

    Set the placeholder in position \a pos to be bound to value \a val
    in the prepared statement. Field numbering starts at 0. If \a type
    is \c TQSql::Out or \c TQSql::InOut, the placeholder will be
    overwritten with data from the database after the exec() call.

    \sa addBindValue(), prepare(), exec()
*/
void TQSqlQuery::bindValue( int pos, const TQVariant& val, TQSql::ParameterType type )
{
    if ( !d->sqlResult || !d->sqlResult->extension() )
	return;
    d->sqlResult->extension()->bindValue( pos, val, type );
}

/*!
    Adds the value \a val to the list of values when using positional
    value binding. The order of the addBindValue() calls determines
    which placeholder a value will be bound to in the prepared query.
    If \a type is \c TQSql::Out or \c TQSql::InOut, the placeholder will
    be overwritten with data from the database after the exec() call.

    \sa bindValue(), prepare(), exec()
*/
void TQSqlQuery::addBindValue( const TQVariant& val, TQSql::ParameterType type )
{
    if ( !d->sqlResult || !d->sqlResult->extension() )
	return;
    d->sqlResult->extension()->addBindValue( val, type );
}


/*!
    \overload

    Binds the placeholder with type \c TQSql::In.
*/
void TQSqlQuery::bindValue( const TQString& placeholder, const TQVariant& val )
{
    bindValue( placeholder, val, TQSql::In );
}

/*!
    \overload

    Binds the placeholder at position \a pos with type \c TQSql::In.
*/
void TQSqlQuery::bindValue( int pos, const TQVariant& val )
{
    bindValue( pos, val, TQSql::In );
}

/*!
    \overload

    Binds the placeholder with type \c TQSql::In.
*/
void TQSqlQuery::addBindValue( const TQVariant& val )
{
    addBindValue( val, TQSql::In );
}

/*!
    Returns the value for the \a placeholder.
*/
TQVariant TQSqlQuery::boundValue( const TQString& placeholder ) const
{
    if ( !d->sqlResult || !d->sqlResult->extension() )
	return TQVariant();
    return d->sqlResult->extension()->boundValue( placeholder );
}

/*!
    \overload

    Returns the value for the placeholder at position \a pos.
*/
TQVariant TQSqlQuery::boundValue( int pos ) const
{
    if ( !d->sqlResult || !d->sqlResult->extension() )
	return TQVariant();
    return d->sqlResult->extension()->boundValue( pos );
}

/*!
    Returns a map of the bound values.

    The bound values can be examined in the following way:
    \code
    TQSqlQuery query;
    ...
    // Examine the bound values - bound using named binding
    TQMap<TQString, TQVariant>::ConstIterator it;
    TQMap<TQString, TQVariant> vals = query.boundValues();
    for ( it = vals.begin(); it != vals.end(); ++it )
        tqWarning( "Placeholder: " + it.key() + ", Value: " + (*it).toString() );
    ...

    // Examine the bound values - bound using positional binding
    TQValueList<TQVariant>::ConstIterator it;
    TQValueList<TQVariant> list = query.boundValues().values();
    int i = 0;
    for ( it = list.begin(); it != list.end(); ++it )
        tqWarning( "Placeholder pos: %d, Value: " + (*it).toString(), i++ );
    ...

    \endcode
*/
TQMap<TQString,TQVariant> TQSqlQuery::boundValues() const
{
    if ( !d->sqlResult || !d->sqlResult->extension() )
	return TQMap<TQString,TQVariant>();
    return d->sqlResult->extension()->boundValues();
}

/*!
    Returns the last query that was executed.

    In most cases this function returns the same as lastQuery(). If a
    prepared query with placeholders is executed on a DBMS that does
    not support it, the preparation of this query is emulated. The
    placeholders in the original query are replaced with their bound
    values to form a new query. This function returns the modified
    query. Useful for debugging purposes.

    \sa lastQuery()
*/
TQString TQSqlQuery::executedQuery() const
{
    return d->executedQuery;
}
#endif // TQT_NO_SQL