175 lines
7.4 KiB
HTML
175 lines
7.4 KiB
HTML
<!DOCTYPE html>
|
|
<html><head>
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
|
|
<link href="../sqlite.css" rel="stylesheet">
|
|
<title>Function Flags</title>
|
|
<!-- path=../ -->
|
|
</head>
|
|
<body>
|
|
<div class=nosearch>
|
|
<a href="../index.html">
|
|
<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite" border="0">
|
|
</a>
|
|
<div><!-- IE hack to prevent disappearing logo --></div>
|
|
<div class="tagline desktoponly">
|
|
Small. Fast. Reliable.<br>Choose any three.
|
|
</div>
|
|
<div class="menu mainmenu">
|
|
<ul>
|
|
<li><a href="../index.html">Home</a>
|
|
<li class='mobileonly'><a href="javascript:void(0)" onclick='toggle_div("submenu")'>Menu</a>
|
|
<li class='wideonly'><a href='../about.html'>About</a>
|
|
<li class='desktoponly'><a href="../docs.html">Documentation</a>
|
|
<li class='desktoponly'><a href="../download.html">Download</a>
|
|
<li class='wideonly'><a href='../copyright.html'>License</a>
|
|
<li class='desktoponly'><a href="../support.html">Support</a>
|
|
<li class='desktoponly'><a href="../prosupport.html">Purchase</a>
|
|
<li class='search' id='search_menubutton'>
|
|
<a href="javascript:void(0)" onclick='toggle_search()'>Search</a>
|
|
</ul>
|
|
</div>
|
|
<div class="menu submenu" id="submenu">
|
|
<ul>
|
|
<li><a href='../about.html'>About</a>
|
|
<li><a href='../docs.html'>Documentation</a>
|
|
<li><a href='../download.html'>Download</a>
|
|
<li><a href='../support.html'>Support</a>
|
|
<li><a href='../prosupport.html'>Purchase</a>
|
|
</ul>
|
|
</div>
|
|
<div class="searchmenu" id="searchmenu">
|
|
<form method="GET" action="../search">
|
|
<select name="s" id="searchtype">
|
|
<option value="d">Search Documentation</option>
|
|
<option value="c">Search Changelog</option>
|
|
</select>
|
|
<input type="text" name="q" id="searchbox" value="">
|
|
<input type="submit" value="Go">
|
|
</form>
|
|
</div>
|
|
</div>
|
|
<script>
|
|
function toggle_div(nm) {
|
|
var w = document.getElementById(nm);
|
|
if( w.style.display=="block" ){
|
|
w.style.display = "none";
|
|
}else{
|
|
w.style.display = "block";
|
|
}
|
|
}
|
|
function toggle_search() {
|
|
var w = document.getElementById("searchmenu");
|
|
if( w.style.display=="block" ){
|
|
w.style.display = "none";
|
|
} else {
|
|
w.style.display = "block";
|
|
setTimeout(function(){
|
|
document.getElementById("searchbox").focus()
|
|
}, 30);
|
|
}
|
|
}
|
|
function div_off(nm){document.getElementById(nm).style.display="none";}
|
|
window.onbeforeunload = function(e){div_off("submenu");}
|
|
/* Disable the Search feature if we are not operating from CGI, since */
|
|
/* Search is accomplished using CGI and will not work without it. */
|
|
if( !location.origin || !location.origin.match || !location.origin.match(/http/) ){
|
|
document.getElementById("search_menubutton").style.display = "none";
|
|
}
|
|
/* Used by the Hide/Show button beside syntax diagrams, to toggle the */
|
|
function hideorshow(btn,obj){
|
|
var x = document.getElementById(obj);
|
|
var b = document.getElementById(btn);
|
|
if( x.style.display!='none' ){
|
|
x.style.display = 'none';
|
|
b.innerHTML='show';
|
|
}else{
|
|
x.style.display = '';
|
|
b.innerHTML='hide';
|
|
}
|
|
return false;
|
|
}
|
|
</script>
|
|
</div>
|
|
<!-- keywords: SQLITE_DETERMINISTIC SQLITE_DIRECTONLY SQLITE_INNOCUOUS SQLITE_SUBTYPE -->
|
|
<div class=nosearch>
|
|
<a href="intro.html"><h2>SQLite C Interface</h2></a>
|
|
<h2>Function Flags</h2>
|
|
</div>
|
|
<blockquote><pre>
|
|
#define SQLITE_DETERMINISTIC 0x000000800
|
|
#define SQLITE_DIRECTONLY 0x000080000
|
|
#define SQLITE_SUBTYPE 0x000100000
|
|
#define SQLITE_INNOCUOUS 0x000200000
|
|
</pre></blockquote>
|
|
<p>
|
|
These constants may be ORed together with the
|
|
<a href="../c3ref/c_any.html">preferred text encoding</a> as the fourth argument
|
|
to <a href="../c3ref/create_function.html">sqlite3_create_function()</a>, <a href="../c3ref/create_function.html">sqlite3_create_function16()</a>, or
|
|
<a href="../c3ref/create_function.html">sqlite3_create_function_v2()</a>.</p>
|
|
|
|
<p><dl>
|
|
<a name="sqlitedeterministic"></a>
|
|
<dt>SQLITE_DETERMINISTIC</dt><dd>
|
|
The SQLITE_DETERMINISTIC flag means that the new function always gives
|
|
the same output when the input parameters are the same.
|
|
The <a href="../lang_corefunc.html#abs">abs() function</a> is deterministic, for example, but
|
|
<a href="../lang_corefunc.html#randomblob">randomblob()</a> is not. Functions must
|
|
be deterministic in order to be used in certain contexts such as
|
|
with the WHERE clause of <a href="../partialindex.html">partial indexes</a> or in <a href="../gencol.html">generated columns</a>.
|
|
SQLite might also optimize deterministic functions by factoring them
|
|
out of inner loops.
|
|
</dd></p>
|
|
|
|
<p><a name="sqlitedirectonly"></a>
|
|
<dt>SQLITE_DIRECTONLY</dt><dd>
|
|
The SQLITE_DIRECTONLY flag means that the function may only be invoked
|
|
from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
|
|
schema structures such as <a href="../lang_createtable.html#ckconst">CHECK constraints</a>, <a href="../lang_createtable.html#dfltval">DEFAULT clauses</a>,
|
|
<a href="../expridx.html">expression indexes</a>, <a href="../partialindex.html">partial indexes</a>, or <a href="../gencol.html">generated columns</a>.
|
|
The SQLITE_DIRECTONLY flags is a security feature which is recommended
|
|
for all <a href="../appfunc.html">application-defined SQL functions</a>, and especially for functions
|
|
that have side-effects or that could potentially leak sensitive
|
|
information.
|
|
</dd></p>
|
|
|
|
<p><a name="sqliteinnocuous"></a>
|
|
<dt>SQLITE_INNOCUOUS</dt><dd>
|
|
The SQLITE_INNOCUOUS flag means that the function is unlikely
|
|
to cause problems even if misused. An innocuous function should have
|
|
no side effects and should not depend on any values other than its
|
|
input parameters. The <a href="../lang_corefunc.html#abs">abs() function</a> is an example of an
|
|
innocuous function.
|
|
The <a href="../lang_corefunc.html#load_extension">load_extension() SQL function</a> is not innocuous because of its
|
|
side effects.
|
|
<p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
|
|
exactly the same. The <a href="../lang_corefunc.html#random">random() function</a> is an example of a
|
|
function that is innocuous but not deterministic.
|
|
<p>Some heightened security settings
|
|
(<a href="../c3ref/c_dbconfig_defensive.html#sqlitedbconfigtrustedschema">SQLITE_DBCONFIG_TRUSTED_SCHEMA</a> and <a href="../pragma.html#pragma_trusted_schema">PRAGMA trusted_schema=OFF</a>)
|
|
disable the use of SQL functions inside views and triggers and in
|
|
schema structures such as <a href="../lang_createtable.html#ckconst">CHECK constraints</a>, <a href="../lang_createtable.html#dfltval">DEFAULT clauses</a>,
|
|
<a href="../expridx.html">expression indexes</a>, <a href="../partialindex.html">partial indexes</a>, and <a href="../gencol.html">generated columns</a> unless
|
|
the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
|
|
are innocuous. Developers are advised to avoid using the
|
|
SQLITE_INNOCUOUS flag for application-defined functions unless the
|
|
function has been carefully audited and found to be free of potentially
|
|
security-adverse side-effects and information-leaks.
|
|
</dd></p>
|
|
|
|
<p><a name="sqlitesubtype"></a>
|
|
<dt>SQLITE_SUBTYPE</dt><dd>
|
|
The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
|
|
<a href="../c3ref/value_subtype.html">sqlite3_value_subtype()</a> to inspect the sub-types of its arguments.
|
|
Specifying this flag makes no difference for scalar or aggregate user
|
|
functions. However, if it is not specified for a user-defined window
|
|
function, then any sub-types belonging to arguments passed to the window
|
|
function may be discarded before the window function is called (i.e.
|
|
sqlite3_value_subtype() will always return 0).
|
|
</dd>
|
|
</dl>
|
|
</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>
|