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<a href="intro.html"><h2>SQLite C Interface</h2></a>
<h2>Pseudo-Random Number Generator</h2>
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<blockquote><pre>
void sqlite3_randomness(int N, void *P);
</pre></blockquote>
<p>
SQLite contains a high-quality pseudo-random number generator (PRNG) used to
select random <a href="../lang_createtable.html#rowid">ROWIDs</a> when inserting new records into a table that
already uses the largest possible <a href="../lang_createtable.html#rowid">ROWID</a>. The PRNG is also used for
the built-in random() and randomblob() SQL functions. This interface allows
applications to access the same PRNG for other purposes.</p>
<p>A call to this routine stores N bytes of randomness into buffer P.
The P parameter can be a NULL pointer.</p>
<p>If this routine has not been previously called or if the previous
call had N less than one or a NULL pointer for P, then the PRNG is
seeded using randomness obtained from the xRandomness method of
the default <a href="../c3ref/vfs.html">sqlite3_vfs</a> object.
If the previous call to this routine had an N of 1 or more and a
non-NULL P then the pseudo-randomness is generated
internally and without recourse to the <a href="../c3ref/vfs.html">sqlite3_vfs</a> xRandomness
method.
</p><p>See also lists of
<a href="objlist.html">Objects</a>,
<a href="constlist.html">Constants</a>, and
<a href="funclist.html">Functions</a>.</p>
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