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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 14:07:11 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 14:07:11 +0000 |
commit | 63847496f14c813a5d80efd5b7de0f1294ffe1e3 (patch) | |
tree | 01c7571c7c762ceee70638549a99834fdd7c411b /www/c3ref/c_deterministic.html | |
parent | Initial commit. (diff) | |
download | sqlite3-63847496f14c813a5d80efd5b7de0f1294ffe1e3.tar.xz sqlite3-63847496f14c813a5d80efd5b7de0f1294ffe1e3.zip |
Adding upstream version 3.45.1.upstream/3.45.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'www/c3ref/c_deterministic.html')
-rw-r--r-- | www/c3ref/c_deterministic.html | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/www/c3ref/c_deterministic.html b/www/c3ref/c_deterministic.html new file mode 100644 index 0000000..5e31f34 --- /dev/null +++ b/www/c3ref/c_deterministic.html @@ -0,0 +1,226 @@ +<!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; +} +var antiRobot = 0; +function antiRobotGo(){ +if( antiRobot!=3 ) return; +antiRobot = 7; +var j = document.getElementById("mtimelink"); +if(j && j.hasAttribute("data-href")) j.href=j.getAttribute("data-href"); +} +function antiRobotDefense(){ +document.body.onmousedown=function(){ +antiRobot |= 2; +antiRobotGo(); +document.body.onmousedown=null; +} +document.body.onmousemove=function(){ +antiRobot |= 2; +antiRobotGo(); +document.body.onmousemove=null; +} +setTimeout(function(){ +antiRobot |= 1; +antiRobotGo(); +}, 100) +antiRobotGo(); +} +antiRobotDefense(); +</script> +<!-- keywords: SQLITE_DETERMINISTIC SQLITE_DIRECTONLY SQLITE_INNOCUOUS SQLITE_RESULT_SUBTYPE SQLITE_SUBTYPE --> +<div class=nosearch> +<a href="../c3ref/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 +#define SQLITE_RESULT_SUBTYPE 0x001000000 +</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>. +<p> +The SQLITE_DIRECTONLY flag is recommended for any +<a href="../appfunc.html">application-defined SQL function</a> +that has side-effects or that could potentially leak sensitive information. +This will prevent attacks in which an application is tricked +into using a database file that has had its schema surreptitiously +modified to invoke the application-defined function in ways that are +harmful. +<p> +Some people say it is good practice to set SQLITE_DIRECTONLY on all +<a href="../appfunc.html">application-defined SQL functions</a>, regardless of whether or not they +are security sensitive, as doing so prevents those functions from being used +inside of the database schema, and thus ensures that the database +can be inspected and modified using generic tools (such as the <a href="../cli.html">CLI</a>) +that do not have access to the application-defined functions. +</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 might call +<a href="../c3ref/value_subtype.html">sqlite3_value_subtype()</a> to inspect the sub-types of its arguments. +This flag instructs SQLite to omit some corner-case optimizations that +might disrupt the operation of the <a href="../c3ref/value_subtype.html">sqlite3_value_subtype()</a> function, +causing it to return zero rather than the correct subtype(). +SQL functions that invokes <a href="../c3ref/value_subtype.html">sqlite3_value_subtype()</a> should have this +property. If the SQLITE_SUBTYPE property is omitted, then the return +value from <a href="../c3ref/value_subtype.html">sqlite3_value_subtype()</a> might sometimes be zero even though +a non-zero subtype was specified by the function argument expression.</p> + +<p><a name="sqliteresultsubtype"></a> + <dt>SQLITE_RESULT_SUBTYPE</dt><dd> +The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call +<a href="../c3ref/result_subtype.html">sqlite3_result_subtype()</a> to cause a sub-type to be associated with its +result. +Every function that invokes <a href="../c3ref/result_subtype.html">sqlite3_result_subtype()</a> should have this +property. If it does not, then the call to <a href="../c3ref/result_subtype.html">sqlite3_result_subtype()</a> +might become a no-op if the function is used as term in an +<a href="../expridx.html">expression index</a>. On the other hand, SQL functions that never invoke +<a href="../c3ref/result_subtype.html">sqlite3_result_subtype()</a> should avoid setting this property, as the +purpose of this property is to disable certain optimizations that are +incompatible with subtypes. +</dd> +</dl> +</p><p>See also lists of + <a href="../c3ref/objlist.html">Objects</a>, + <a href="../c3ref/constlist.html">Constants</a>, and + <a href="../c3ref/funclist.html">Functions</a>.</p> + |