File: dbput.html

package info (click to toggle)
db5.3 5.3.28%2Bdfsg1-0.5
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 158,360 kB
  • sloc: ansic: 448,411; java: 111,824; tcl: 80,544; sh: 44,326; cs: 33,697; cpp: 21,604; perl: 14,557; xml: 10,799; makefile: 4,077; yacc: 1,003; awk: 965; sql: 801; erlang: 342; python: 216; php: 24; asm: 14
file content (567 lines) | stat: -rw-r--r-- 26,714 bytes parent folder | download | duplicates (8)
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
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Db::put()</title>
    <link rel="stylesheet" href="apiReference.css" type="text/css" />
    <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
    <link rel="start" href="index.html" title="Berkeley DB C++ API Reference" />
    <link rel="up" href="db.html" title="Chapter 2.  The Db Handle" />
    <link rel="prev" href="dbopen.html" title="Db::open()" />
    <link rel="next" href="dbremove.html" title="Db::remove()" />
  </head>
  <body>
    <div xmlns="" class="navheader">
      <div class="libver">
        <p>Library Version 11.2.5.3</p>
      </div>
      <table width="100%" summary="Navigation header">
        <tr>
          <th colspan="3" align="center">Db::put()</th>
        </tr>
        <tr>
          <td width="20%" align="left"><a accesskey="p" href="dbopen.html">Prev</a> </td>
          <th width="60%" align="center">Chapter 2. 
                The Db Handle
        </th>
          <td width="20%" align="right"> <a accesskey="n" href="dbremove.html">Next</a></td>
        </tr>
      </table>
      <hr />
    </div>
    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
        <div>
          <div>
            <h2 class="title" style="clear: both"><a id="dbput"></a>Db::put()</h2>
          </div>
        </div>
      </div>
      <pre class="programlisting">#include &lt;db_cxx.h&gt;
 
int
Db::put(DbTxn *txnid, Dbt *key, Dbt *data, u_int32_t flags);</pre>
      <p>
         The <code class="methodname">Db::put()</code> method stores key/data
         pairs in the database.  The default behavior of the
         <code class="methodname">Db::put()</code> function is to enter the new
         key/data pair, replacing any previously existing key if duplicates
         are disallowed, or adding a duplicate data item if duplicates are
         allowed.  If the database supports duplicates, the
         <code class="methodname">Db::put()</code> method adds the new data value
         at the end of the duplicate set.  If the database supports sorted
         duplicates, the new data value is inserted at the correct sorted
         location.
     </p>
      <p>
         Unless otherwise specified, the
         <code class="methodname">Db::put()</code> <span>
            
            <span>
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.
            </span>
        </span>
    </p>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idm573432"></a>Parameters</h3>
            </div>
          </div>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp3631152"></a>txnid</h4>
              </div>
            </div>
          </div>
          <p>
                  If the operation is part of an application-specified
                  transaction, the <span class="bold"><strong>txnid</strong></span>
                  parameter is a transaction handle returned from 
                  <a class="xref" href="txnbegin.html" title="DbEnv::txn_begin()">DbEnv::txn_begin()</a>; if
                  the operation is part of a Berkeley DB Concurrent Data
                  Store group, the <span class="bold"><strong>txnid</strong></span>
                  parameter is a handle returned from 
                  <a class="xref" href="envcdsgroup_begin.html" title="DbEnv::cdsgroup_begin()">DbEnv::cdsgroup_begin()</a>; 
                  otherwise NULL.  If no transaction handle is specified,
                  but the operation occurs in a transactional database, the
                  operation will be implicitly transaction protected.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idm219240"></a>key</h4>
              </div>
            </div>
          </div>
          <p>
                  The key <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>  operated on.
             </p>
          <p>
                 If creating a new record in a Heap database, the 
                 key <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>
                 must be empty. The <code class="literal">put</code>
                 method will return the new record's 
                 <a class="link" href="db_heap_rid.html" title="DbHeapRecordId">Record ID (RID)</a> 
                 in the key <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp1230496"></a>data</h4>
              </div>
            </div>
          </div>
          <p>
                  The data <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>  operated on.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp1617704"></a>flags</h4>
              </div>
            </div>
          </div>
          <p>
                  The <span class="bold"><strong>flags</strong></span> parameter must be set to 0
                  or one of the following values:
             </p>
          <div class="itemizedlist">
            <ul type="disc">
              <li>
                <p><a id="dbput_DB_APPEND"></a>
                          <code class="literal">DB_APPEND</code>
                     </p>
                <p>
                         Append the key/data pair to the end of the
                         database.  For the DB_APPEND flag to be specified,
                         the underlying database must be a Heap, Queue or
                         Recno database.  The record number allocated to
                         the record is returned in the specified 
                         <span class="bold"><strong>key</strong></span>.
                    </p>
                <p>
                         There is a minor behavioral difference between the Recno
                         and Queue access methods for the DB_APPEND flag.  If a
                         transaction enclosing a
                         <code class="methodname">Db::put()</code> operation with the
                         DB_APPEND flag aborts, the record number may be
                         reallocated in a subsequent <code class="literal">DB_APPEND</code>
                         operation if you are using the Recno access method, but it
                         will not be reallocated if you are using the Queue access
                         method.
                    </p>
                <p>
                        For a Heap database, if the put operation results
                        in the creation of a new record, then this flag is
                        required. 
                    </p>
              </li>
              <li>
                <p><a id="put_DB_NODUPDATA"></a>
                          <code class="literal">DB_NODUPDATA</code>
                    </p>
                <p>
                         In the case of the Btree and Hash access methods,
                         enter the new key/data pair only if it does not
                         already appear in the database.
                    </p>
                <p>
                         The DB_NODUPDATA flag may only be specified if the
                         underlying database has been configured to support
                         sorted duplicates.  The DB_NODUPDATA flag may not
                         be specified to the Queue or Recno access methods.
                    </p>
                <p>
                         The <code class="methodname">Db::put()</code> method will return 
                         <a class="xref" href="dbcput.html#dbcput_DB_KEYEXIST" title="DB_KEYEXIST">DB_KEYEXIST</a>
                         if DB_NODUPDATA is set and the key/data pair already appears in the
                         database.
                    </p>
              </li>
              <li>
                <p><a id="put_DB_NOOVERWRITE"></a>
                          <code class="literal">DB_NOOVERWRITE</code>
                    </p>
                <p>
                         Enter the new key/data pair only if the key does
                         not already appear in the database.  The
                         <code class="methodname">Db::put()</code> method call
                         with the DB_NOOVERWRITE flag set will fail if the
                         key already exists in the database, even if the
                         database supports duplicates.
                    </p>
                <p>
                         The <code class="methodname">Db::put()</code> method will return 
                         <a class="xref" href="dbcput.html#dbcput_DB_KEYEXIST" title="DB_KEYEXIST">DB_KEYEXIST</a>  
                         if DB_NOOVERWRITE is set and the key already appears in the database.
                    </p>
                <p>
                        This enforcement of uniqueness of keys applies only
                        to the primary key.  The behavior of insertions
                        into secondary databases is not affected by the
                        DB_NOOVERWRITE flag.  In particular, the insertion
                        of a record that would result in the creation of a
                        duplicate key in a secondary database that allows
                        duplicates would not be prevented by the use of
                        this flag.
                    </p>
              </li>
              <li>
                <p><a id="put_DB_MULTIPLE"></a>
                          <code class="literal">DB_MULTIPLE</code>
                    </p>
                <p>
                        Put multiple data items using keys from the buffer
                        to which the <span class="bold"><strong>key</strong></span>
                        parameter refers and data values from the buffer to
                        which the <span class="bold"><strong>data</strong></span>
                        parameter refers.
                    </p>
                <p>
                        To put records in bulk with the btree or hash
                        access methods, construct bulk buffers in the
                        <span class="bold"><strong>key</strong></span> and <span class="bold"><strong>data</strong></span> <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a> using <a class="xref" href="dbmultipledatabuilder.html" title="DbMultipleDataBuilder">DbMultipleDataBuilder</a>.  To
                        put records in bulk with the recno or queue access
                        methods, construct bulk buffers in the <span class="bold"><strong>data</strong></span> <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a> as before, but
                        construct the <span class="bold"><strong>key</strong></span>
                        <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a> using <a class="xref" href="dbmultiplerecnodatabuilder.html" title="DbMultipleRecnoDataBuilder">DbMultipleRecnoDataBuilder</a>
                        with a data size of zero.
                    </p>
                <p>
                        A successful bulk operation is logically equivalent
                        to a loop through each key/data pair, performing a
                        <a class="xref" href="dbput.html" title="Db::put()">Db::put()</a> for each one.
                    </p>
                <p>
                        See 
                        <a class="xref" href="dbt.html#dbtlist" title="DBT and Bulk Operations">DBT and Bulk Operations</a> 
                        for more information on working with bulk
                        updates.
                    </p>
                <p>
                        The <code class="literal">DB_MULTIPLE</code> flag may only be
                        used alone, or with the
                        <code class="literal">DB_OVERWRITE_DUP</code> option.
                    </p>
              </li>
              <li>
                <p><a id="put_DB_MULTIPLE_KEY"></a>
                          <code class="literal">DB_MULTIPLE_KEY</code>
                    </p>
                <p>
                        Put multiple data items using keys and data from
                        the buffer to which the <span class="bold"><strong>key</strong></span> parameter refers.
                    </p>
                <p>
                        To put records in bulk with the btree or hash
                        access methods, construct a bulk buffer in the
                        <span class="bold"><strong>key</strong></span> <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a> using <a class="xref" href="dbmultiplekeydatabuilder.html" title="DbMultipleKeyDataBuilder">DbMultipleKeyDataBuilder</a>.
                        To put records in bulk with the recno or queue
                        access methods, construct a bulk
                        buffer in the <span class="bold"><strong>key</strong></span>
                        <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a> using <a class="xref" href="dbmultiplerecnodatabuilder.html" title="DbMultipleRecnoDataBuilder">DbMultipleRecnoDataBuilder</a>.
                    </p>
                <p>
                        See <a class="xref" href="dbt.html#dbtlist" title="DBT and Bulk Operations">DBT and Bulk Operations</a> for more information on working with bulk
                        updates.
                    </p>
                <p>
                        The <code class="literal">DB_MULTIPLE_KEY</code> flag may
                        only be used alone, or with the
                        <code class="literal">DB_OVERWRITE_DUP</code> option.
                    </p>
              </li>
              <li>
                <p><a id="put_DB_OVERWRITE_DUP"></a>
                         <code class="literal">DB_OVERWRITE_DUP</code>
                     </p>
                <p>
                         Ignore duplicate records when overwriting records
                         in a database configured for sorted duplicates.
                     </p>
                <p>
                         Normally, if a database is configured for sorted
                         duplicates, an attempt to put a record that
                         compares identically to a record already existing
                         in the database will fail. Using this flag causes
                         the put to silently proceed, without failure.
                     </p>
                <p>
                         This flag is extremely useful when performing bulk
                         puts (using the <code class="literal">DB_MULTIPLE</code> or
                         <code class="literal">DB_MULTIPLE_KEY</code> flags).
                         Depending on the number of records you are writing
                         to the database with a bulk put, you may not want
                         the operation to fail in the event that a
                         duplicate record is encountered. Using this flag
                         along with the <code class="literal">DB_MULTIPLE</code> or
                         <code class="literal">DB_MULTIPLE_KEY</code> flags allows
                         the bulk put to complete, even if a duplicate
                         record is encountered.
                     </p>
                <p>
                         This flag is also useful if you are using a custom
                         comparison function that compares only part of the
                         data portion of a record. In this case, two
                         records can compare equally when, in fact, they
                         are not equal. This flag allows the put to
                         complete, even if your custom comparison routine
                         claims the two records are equal.
                     </p>
              </li>
            </ul>
          </div>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp1907688"></a>Errors</h3>
            </div>
          </div>
        </div>
        <p>
             The <code class="methodname">Db::put()</code> <span>
            
            <span>
                method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 
                exception, encapsulating one of the following non-zero errors, or return one
                of the following non-zero errors:
            </span>
        </span>
        </p>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp3972656"></a>DB_FOREIGN_CONFLICT</h4>
              </div>
            </div>
          </div>
          <p>
                A <a class="link" href="dbassociate_foreign.html" title="Db::associate_foreign()">foreign key constraint violation</a> 
                has occurred. This can be caused by one of two things:
            </p>
          <div class="orderedlist">
            <ol type="1">
              <li>
                <p>
                            An attempt was made to add a record to a
                            constrained database, and the key used for that
                            record does not exist in the foreign key
                            database.
                        </p>
              </li>
              <li>
                <p>
                            <a class="link" href="dbassociate_foreign.html#associate_foreign_DB_FOREIGN_ABORT">DB_FOREIGN_ABORT</a> 
                            was declared for a foreign key database, and then
                            subsequently a record was deleted from the
                            foreign key database without first removing it
                            from the constrained secondary database.
                        </p>
              </li>
            </ol>
          </div>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp2481304"></a>DB_HEAP_FULL</h4>
              </div>
            </div>
          </div>
          <p>
                An attempt was made to add or update a record in a Heap
                database. However, the size of the database was constrained
                using the
                <a class="xref" href="dbset_heapsize.html" title="Db::set_heapsize()">Db::set_heapsize()</a>
                method, and that limit has been reached.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp4300800"></a><span>DbDeadlockException or </span>DB_LOCK_DEADLOCK</h4>
              </div>
            </div>
          </div>
          <p>
                A transactional database environment operation was selected to resolve
                a deadlock.
            </p>
          <p>
                <a class="xref" href="dbdeadlock.html" title="DbDeadlockException">DbDeadlockException</a> is thrown if
                your Berkeley DB API is configured to throw exceptions.
                Otherwise, <code class="literal">DB_LOCK_DEADLOCK</code> is returned.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp1820472"></a><span>DbLockNotGrantedException or </span>DB_LOCK_NOTGRANTED</h4>
              </div>
            </div>
          </div>
          <p>
                A Berkeley DB Concurrent Data Store database environment configured
                for lock timeouts was unable to grant a lock in the allowed time.
            </p>
          <p>
                You attempted to open a database handle that is configured
                for no waiting exclusive locking, but the exclusive lock could not be
                immediately obtained. See
                <a class="xref" href="dbset_lk_exclusive.html" title="Db::set_lk_exclusive()">Db::set_lk_exclusive()</a>
                for more information.
            </p>
          <p>
                <a class="xref" href="dblocknotgranted.html" title="DbLockNotGrantedException">DbLockNotGrantedException</a> is thrown if
                your Berkeley DB API is configured to throw exceptions.
                Otherwise, <code class="literal">DB_LOCK_NOTGRANTED</code> is returned.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idm93440"></a> <span>DbRepHandleDeadException or</span> DB_REP_HANDLE_DEAD</h4>
              </div>
            </div>
          </div>
          <p>
                When a client synchronizes with the master, it is possible for committed
                transactions to be rolled back. This invalidates all  the database and cursor
                handles opened in the replication environment. Once this occurs, an attempt to use
                such a handle will 
                <span>
                    throw a <a class="xref" href="dbrephandledead.html" title="DbRepHandleDeadException">DbRepHandleDeadException</a> (if
                    your application is configured to throw exceptions), or 
                </span>
                return <code class="literal">DB_REP_HANDLE_DEAD</code>.
                The application will need to discard the handle and open a new one in order to
                continue processing.
            </p>
        </div>
        <a id="dbput_DB_REP_LOCKOUT"></a>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idm306912"></a><span>DbDeadlockException or </span>DB_REP_LOCKOUT</h4>
              </div>
            </div>
          </div>
          <p>
                The operation was blocked by client/master synchronization.
            </p>
          <p>
                <a class="xref" href="dbdeadlock.html" title="DbDeadlockException">DbDeadlockException</a> is thrown if
                your Berkeley DB API is configured to throw exceptions.
                Otherwise, <code class="literal">DB_REP_LOCKOUT</code> is returned.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idm366600"></a>EACCES</h4>
              </div>
            </div>
          </div>
          <p>
                An attempt was made to modify a read-only database.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp671256"></a>EINVAL</h4>
              </div>
            </div>
          </div>
          <p>
              If a record number of 0 was specified; an attempt was made to add a
              record to a fixed-length database that was too large to fit; an
              attempt was made to do a partial put; an attempt was made to add a
              record to a secondary index; or if an invalid flag value or parameter
              was specified.
         </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idm562800"></a>ENOSPC</h4>
              </div>
            </div>
          </div>
          <p>
                A btree exceeded the maximum btree depth (255).
            </p>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idm566984"></a>Class</h3>
            </div>
          </div>
        </div>
        <p>
                    <a class="link" href="db.html" title="Chapter 2.  The Db Handle">Db</a>  
            </p>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp190536"></a>See Also</h3>
            </div>
          </div>
        </div>
        <p>
                     <a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a> 
                </p>
      </div>
    </div>
    <div class="navfooter">
      <hr />
      <table width="100%" summary="Navigation footer">
        <tr>
          <td width="40%" align="left"><a accesskey="p" href="dbopen.html">Prev</a> </td>
          <td width="20%" align="center">
            <a accesskey="u" href="db.html">Up</a>
          </td>
          <td width="40%" align="right"> <a accesskey="n" href="dbremove.html">Next</a></td>
        </tr>
        <tr>
          <td width="40%" align="left" valign="top">Db::open() </td>
          <td width="20%" align="center">
            <a accesskey="h" href="index.html">Home</a>
          </td>
          <td width="40%" align="right" valign="top"> Db::remove()</td>
        </tr>
      </table>
    </div>
  </body>
</html>