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diff --git a/www/c3ref/c_vtab_constraint_support.html b/www/c3ref/c_vtab_constraint_support.html new file mode 100644 index 0000000..2dd68ee --- /dev/null +++ b/www/c3ref/c_vtab_constraint_support.html @@ -0,0 +1,203 @@ +<!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>Virtual Table Configuration Options</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_VTAB_CONSTRAINT_SUPPORT SQLITE_VTAB_DIRECTONLY SQLITE_VTAB_INNOCUOUS SQLITE_VTAB_USES_ALL_SCHEMAS {virtual table configuration option} {virtual table configuration options} --> +<div class=nosearch> +<a href="../c3ref/intro.html"><h2>SQLite C Interface</h2></a> +<h2>Virtual Table Configuration Options</h2> +</div> +<blockquote><pre> +#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 +#define SQLITE_VTAB_INNOCUOUS 2 +#define SQLITE_VTAB_DIRECTONLY 3 +#define SQLITE_VTAB_USES_ALL_SCHEMAS 4 +</pre></blockquote> +<p> +These macros define the various options to the +<a href="../c3ref/vtab_config.html">sqlite3_vtab_config()</a> interface that <a href="../vtab.html">virtual table</a> implementations +can use to customize and optimize their behavior.</p> + +<p><dl> +<a name="sqlitevtabconstraintsupport"></a> + +<dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> +<dd>Calls of the form +<a href="../c3ref/vtab_config.html">sqlite3_vtab_config</a>(db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, +where X is an integer. If X is zero, then the <a href="../vtab.html">virtual table</a> whose +<a href="../vtab.html#xcreate">xCreate</a> or <a href="../vtab.html#xconnect">xConnect</a> method invoked <a href="../c3ref/vtab_config.html">sqlite3_vtab_config()</a> does not +support constraints. In this configuration (which is the default) if +a call to the <a href="../vtab.html#xupdate">xUpdate</a> method returns <a href="../rescode.html#constraint">SQLITE_CONSTRAINT</a>, then the entire +statement is rolled back as if <a href="../lang_conflict.html">OR ABORT</a> had been +specified as part of the users SQL statement, regardless of the actual +ON CONFLICT mode specified.</p> + +<p>If X is non-zero, then the virtual table implementation guarantees +that if <a href="../vtab.html#xupdate">xUpdate</a> returns <a href="../rescode.html#constraint">SQLITE_CONSTRAINT</a>, it will do so before +any modifications to internal or persistent data structures have been made. +If the <a href="../lang_conflict.html">ON CONFLICT</a> mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite +is able to roll back a statement or database transaction, and abandon +or continue processing the current SQL statement as appropriate. +If the ON CONFLICT mode is REPLACE and the <a href="../vtab.html#xupdate">xUpdate</a> method returns +<a href="../rescode.html#constraint">SQLITE_CONSTRAINT</a>, SQLite handles this as if the ON CONFLICT mode +had been ABORT.</p> + +<p>Virtual table implementations that are required to handle OR REPLACE +must do so within the <a href="../vtab.html#xupdate">xUpdate</a> method. If a call to the +<a href="../c3ref/vtab_on_conflict.html">sqlite3_vtab_on_conflict()</a> function indicates that the current ON +CONFLICT policy is REPLACE, the virtual table implementation should +silently replace the appropriate rows within the xUpdate callback and +return SQLITE_OK. Or, if this is not possible, it may return +SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT +constraint handling. +</dd></p> + +<p><a name="sqlitevtabdirectonly"></a> +<dt>SQLITE_VTAB_DIRECTONLY</dt> +<dd>Calls of the form +<a href="../c3ref/vtab_config.html">sqlite3_vtab_config</a>(db,SQLITE_VTAB_DIRECTONLY) from within the +the <a href="../vtab.html#xconnect">xConnect</a> or <a href="../vtab.html#xcreate">xCreate</a> methods of a <a href="../vtab.html">virtual table</a> implementation +prohibits that virtual table from being used from within triggers and +views. +</dd></p> + +<p><a name="sqlitevtabinnocuous"></a> +<dt>SQLITE_VTAB_INNOCUOUS</dt> +<dd>Calls of the form +<a href="../c3ref/vtab_config.html">sqlite3_vtab_config</a>(db,SQLITE_VTAB_INNOCUOUS) from within the +the <a href="../vtab.html#xconnect">xConnect</a> or <a href="../vtab.html#xcreate">xCreate</a> methods of a <a href="../vtab.html">virtual table</a> implementation +identify that virtual table as being safe to use from within triggers +and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the +virtual table can do no serious harm even if it is controlled by a +malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS +flag unless absolutely necessary. +</dd></p> + +<p><a name="sqlitevtabusesallschemas"></a> +<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt> +<dd>Calls of the form +<a href="../c3ref/vtab_config.html">sqlite3_vtab_config</a>(db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the +the <a href="../vtab.html#xconnect">xConnect</a> or <a href="../vtab.html#xcreate">xCreate</a> methods of a <a href="../vtab.html">virtual table</a> implementation +instruct the query planner to begin at least a read transaction on +all schemas ("main", "temp", and any ATTACH-ed databases) whenever the +virtual table is used. +</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> + |