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<title>Berkeley DB Reference Guide: Storing records with a cursor</title>
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<td><h3><dl><dt>Berkeley DB Reference Guide:<dd>Access Methods</dl></h3></td>
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<p>
<h3 align=center>Storing records with a cursor</h3>
<p>The <a href="../../api_c/dbc_put.html">DBcursor->c_put</a> method stores records into the database using a cursor. In
general, <a href="../../api_c/dbc_put.html">DBcursor->c_put</a> takes a key and inserts the associated data
into the database, at a location controlled by a specified flag.</p>
<p>There are several flags that you can set to customize storage:</p>
<dl compact>
<dt><a href="../../api_c/dbc_put.html#DB_AFTER">DB_AFTER</a><dd>Create a new record, immediately after the record to which the cursor
refers.
<dt><a href="../../api_c/dbc_put.html#DB_BEFORE">DB_BEFORE</a><dd>Create a new record, immediately before the record to which the cursor
refers.
<dt><a href="../../api_c/dbc_get.html#DB_CURRENT">DB_CURRENT</a><dd>Replace the data part of the record to which the cursor refers.
<dt><a href="../../api_c/dbc_put.html#DB_KEYFIRST">DB_KEYFIRST</a><dd>Create a new record as the first of the duplicate records for the
supplied key.
<dt><a href="../../api_c/dbc_put.html#DB_KEYLAST">DB_KEYLAST</a><dd>Create a new record, as the last of the duplicate records for the supplied
key.
</dl>
<p>In all cases, the cursor is repositioned by a <a href="../../api_c/dbc_put.html">DBcursor->c_put</a> operation
to point to the newly inserted key/data pair in the database.</p>
<p>The following is a code example showing a cursor storing two data items
in a database that supports duplicate data items:</p>
<blockquote><pre>int
store(dbp)
DB *dbp;
{
DBC *dbcp;
DBT key, data;
int ret;
<p>
/*
* The DB handle for a Btree database supporting duplicate data
* items is the argument; acquire a cursor for the database.
*/
if ((ret = dbp->cursor(dbp, NULL, &dbcp, 0)) != 0) {
dbp->err(dbp, ret, "DB->cursor");
goto err;
}
<p>
/* Initialize the key. */
memset(&key, 0, sizeof(key));
key.data = "new key";
key.size = strlen(key.data) + 1;
<p>
/* Initialize the data to be the first of two duplicate records. */
memset(&data, 0, sizeof(data));
data.data = "new key's data: entry #1";
data.size = strlen(data.data) + 1;
<p>
/* Store the first of the two duplicate records. */
if ((ret = dbcp->c_put(dbcp, &key, &data, DB_KEYFIRST)) != 0)
dbp->err(dbp, ret, "DB->cursor");
<p>
/* Initialize the data to be the second of two duplicate records. */
data.data = "new key's data: entry #2";
data.size = strlen(data.data) + 1;
<p>
/*
* Store the second of the two duplicate records. No duplicate
* record sort function has been specified, so we explicitly
* store the record as the last of the duplicate set.
*/
if ((ret = dbcp->c_put(dbcp, &key, &data, DB_KEYLAST)) != 0)
dbp->err(dbp, ret, "DB->cursor");
<p>
err: if ((ret = dbcp->c_close(dbcp)) != 0)
dbp->err(dbp, ret, "DBcursor->close");
<p>
return (0);
}</pre></blockquote>
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