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37      <p>
38        You replace the data for a database record by using
39        
40
41        
42
43        <span>
44            <tt class="methodname">DBC-&gt;put()</tt>
45            
46            with the <tt class="literal">DB_CURRENT</tt> flag.
47        </span>
48            
49    </p>
50      <a id="c_cursor9"></a>
51      <pre class="programlisting">#include &lt;db.h&gt;
52#include &lt;string.h&gt;
53
54...
55
56DB *dbp;
57DBC *cursorp;
58DBT key, data;
59char *key1str = "My first string";
60char *replacement_data = "replace me";
61int ret;
62
63/* Initialize our DBTs. */
64memset(&amp;key, 0, sizeof(DBT));
65memset(&amp;data, 0, sizeof(DBT));
66
67/* Set up our DBTs */
68key.data = key1str;
69key.size = strlen(key1str) + 1;
70
71/* Database open omitted */
72
73/* Get the cursor */
74dbp-&gt;cursor(dbp, NULL, &amp;cursorp, 0);
75
76/* Position the cursor */
77ret = cursorp-&gt;get(cursorp, &amp;key, &amp;data, DB_SET);
78if (ret == 0) {
79    data.data = replacement_data;
80    data.size = strlen(replacement_data) + 1;
81    cursorp-&gt;put(cursorp, &amp;key, &amp;data, DB_CURRENT);
82}
83
84/* Cursors must be closed */
85if (cursorp != NULL) 
86    cursorp-&gt;close(cursorp); 
87
88if (dbp != NULL)
89    dbp-&gt;close(dbp, 0);</pre>
90      <p>
91        Note that you cannot change a record's key using this method; the key
92        parameter is always ignored when you replace a record.
93    </p>
94      <p>
95        When replacing the data portion of a record, if you are replacing a
96        record that is a member of a sorted duplicates set, then the replacement
97        will be successful only if the new record sorts identically to the old
98        record. This means that if you are replacing a record that is a member
99        of a sorted duplicates set, and if you are using the default
100        lexicographic sort, then the replacement will fail due to violating the
101        sort order. However, if you
102        provide a custom sort routine that, for example, sorts based on just a
103        few bytes out of the data item, then potentially you can perform
104        a direct replacement and still not violate the restrictions described
105        here.
106    </p>
107      <p>
108            <span>Under these circumstances, if</span>
109            
110        you want to replace the data contained by a duplicate record, 
111            <span>
112                and you are not using a custom sort routine, then
113            </span>
114        delete the record and create a new record with the desired key and data.
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