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diff --git a/www/uri.html b/www/uri.html new file mode 100644 index 0000000..5d7409b --- /dev/null +++ b/www/uri.html @@ -0,0 +1,380 @@ +<!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>Uniform Resource Identifiers</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> +<div class=fancy> +<div class=nosearch> +<div class="fancy_title"> +Uniform Resource Identifiers +</div> +</div> + + + + + +<h1 id="uri_filenames_in_sqlite"><span>1. </span>URI Filenames In SQLite</h1> + +<p> +Beginning with <a href="releaselog/3_7_7.html">version 3.7.7</a> (2011-06-23), +the SQLite database file argument to the +<a href="c3ref/open.html">sqlite3_open()</a>, <a href="c3ref/open.html">sqlite3_open16()</a>, and <a href="c3ref/open.html">sqlite3_open_v2()</a> interfaces +and to the <a href="lang_attach.html">ATTACH</a> command can be specified +either as an ordinary filename or as a Uniform Resource Identifier or URI. +The advantage of using a URI filename is that query parameters on the URI can +be used to control details of the newly created database connection. +For example, an alternative <a href="vfs.html">VFS</a> can be specified using a +"vfs=" query parameter. +Or the database can be opened read-only by using "mode=ro" as a query +parameter. +</p> + +<h1 id="backwards_compatibility"><span>2. </span>Backwards Compatibility</h1> + +<p> +In order to maintain full backwards compatibility for legacy applications, +the URI filename capability is disabled by default. +URI filenames can be enabled or disabled using the <a href="compile.html#use_uri">SQLITE_USE_URI=1</a> +or <a href="compile.html#use_uri">SQLITE_USE_URI=0</a> compile-time options. +The compile-time setting for URI filenames can be changed +at start-time using the <a href="c3ref/config.html">sqlite3_config</a>(<a href="c3ref/c_config_covering_index_scan.html#sqliteconfiguri">SQLITE_CONFIG_URI</a>,1) +or <a href="c3ref/config.html">sqlite3_config</a>(<a href="c3ref/c_config_covering_index_scan.html#sqliteconfiguri">SQLITE_CONFIG_URI</a>,0) configuration calls. +Regardless of the compile-time or start-time settings, URI filenames +can be enabled for individual database connections by including the +<a href="c3ref/c_open_autoproxy.html">SQLITE_OPEN_URI</a> bit in the set of bits passed as the F parameter +to <a href="c3ref/open.html">sqlite3_open_v2(N,P,F,V)</a>. +</p> + +<p> +If URI filenames are recognized when the database connection is originally +opened, then URI filenames will also be recognized on <a href="lang_attach.html">ATTACH</a> statements. +Similarly, if URI filenames are not recognized when the database connection +is first opened, they will not be recognized by <a href="lang_attach.html">ATTACH</a>. +</p> + +<p> +Since SQLite always interprets any filename that does not begin +with "<tt>file:</tt>" +as an ordinary filename regardless of the URI setting, and because it is +very unusual to have an actual file begin with "<tt>file:</tt>", +it is safe for most applications to enable URI processing even if URI +filenames are not currently being used. +</p> + +<h1 id="uri_format"><span>3. </span>URI Format</h1> + +<p> +According to <a href="http://tools.ietf.org/html/rfc3986">RFC 3986</a>, a URI consists +of a scheme, an authority, a path, a query string, and a fragment. The +scheme is always required. One of either the authority or the path is also +always required. The query string and fragment are optional. +</p> + +<p> +SQLite uses the "<tt>file:</tt>" URI syntax to identify database files. +SQLite strives to interpret file: URIs in exactly the same way as +popular web-browsers such as +<a href="http://www.mozilla.com/en-US/firefox/new/">Firefox</a>, +<a href="http://www.google.com/chrome/">Chrome</a>, +<a href="http://www.apple.com/safari/">Safari</a>, +<a href="http://windows.microsoft.com/en-US/internet-explorer/products/ie/home">Internet Explorer</a>, and +<a href="http://www.opera.com/">Opera</a>, +and command-line programs such as +<a href="http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/start.mspx">Windows "start"</a> and the Mac OS-X +<a href="http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man1/open.1.html">"open"</a> command. +A succinct summary of the URI parsing rules follows: +</p> + +<ul> +<li> The scheme of the URI must be "<tt>file:</tt>". Any other scheme + results in the input being treated as an ordinary filename. +</li><li> The authority may be omitted, may be blank, or may be + "<tt>localhost</tt>". Any other authority results in an error. + Exception: If SQLite is compiled with <a href="compile.html#allow_uri_authority">SQLITE_ALLOW_URI_AUTHORITY</a> + then any authority value other than "localhost" is passed through to the + underlying operating system as a UNC filename. +</li><li> The path is optional if the authority is present. If the authority + is omitted then the path is required. +</li><li> The query string is optional. If the query string is present, then + all query parameters are passed through into the xOpen method of + the underlying <a href="vfs.html">VFS</a>. +</li><li> The fragment is optional. If present, it is ignored. +</li></ul> + +<p>Zero or more escape sequences of the form "<b>%<i>HH</i></b>" +(where <b><i>H</i></b> represents any hexadecimal digit) can occur +in the path, query string, or fragment.</p> + +<p>A filename that is not a well-formed URI is interpreted as an +ordinary filename.</p> + +<p>URIs are processed as UTF8 text. +The filename argument sqlite3_open16() is converted from UTF16 +native byte order into UTF8 prior to processing. + +</p><h2 id="the_uri_path"><span>3.1. </span>The URI Path</h2> + +<p>The path component of the URI specifies the disk file that is the +SQLite database to be opened. If the path component is omitted, then +the database is stored in a temporary file that will be automatically +deleted when the database connection closes. If the authority section +is present, then the path is always an absolute pathname. If the +authority section is omitted, then the path is an absolute pathname if it +begins with the "/" character (ASCII code 0x2f) and is a relative +pathname otherwise. On windows, if the absolute path begins with +"<b>/<i>X</i>:/</b>" where <b><i>X</i></b> is any single ASCII alphabetic +character ("a" through "z" or "A" through "Z") then the "<b><i>X:</i></b>" +is understood to be the drive letter of the volume containing the file, +not the toplevel directory. + +</p><p>An ordinary filename can usually be converted into an equivalent URI +by the steps shown below. The one exception is that a relative windows +pathname with a drive letter cannot be converted directly into a URI; it must +be changed into an absolute pathname first.</p> + +<ol> +<li>Convert all "<tt>?</tt>" characters into "<tt>%3f</tt>". +</li><li>Convert all "<tt>#</tt>" characters into "<tt>%23</tt>". +</li><li>On windows only, convert all "<tt>\</tt>" characters into "<tt>/</tt>". +</li><li>Convert all sequences of two or more "<tt>/</tt>" characters into a + single "<tt>/</tt>" character. +</li><li>On windows only, if the filename begins with a drive letter, prepend + a single "<tt>/</tt>" character. +</li><li>Prepend the "<tt>file:</tt>" scheme. +</li></ol> + +<h2 id="query_string"><span>3.2. </span>Query String</h2> + +<p>A URI filename can optionally be followed by a query string. +The query string consists of text following the first "<tt>?</tt>" +character but excluding the optional fragment that begins with +"<tt>#</tt>". The query string is divided into key/value pairs. +We usually refer to these key/value pairs as "query parameters". +Key/value pairs are separated by a single "<tt>&</tt>" character. +The key comes first and is separated from the value by a single +"<tt>=</tt>" character. +Both key and value may contain <b>%HH</b> escape sequences.</p> + +<p> +The text of query parameters is appended to the filename argument of +the xOpen method of the <a href="vfs.html">VFS</a>. +Any %HH escape sequences in the query parameters are resolved prior to +being appended to the xOpen filename. +A single zero-byte separates the xOpen filename argument from the key of +the first query parameters, each key and value, and each subsequent key +from the prior value. +The list of query parameters appended to the xOpen filename +is terminated by a single zero-length key. +Note that the value of a query parameter can be an empty string. +</p> + +<a name="coreqp"></a> + +<h2 id="recognized_query_parameters"><span>3.3. </span>Recognized Query Parameters</h2> + +<p> +Some query parameters are interpreted by the SQLite core and used to +modify the characteristics of the new connection. All query parameters +are always passed through into the xOpen method of the <a href="vfs.html">VFS</a> even if +they are previously read and interpreted by the SQLite core. +</p> + +<p> +The following query parameters are recognized by SQLite as of +<a href="releaselog/3_15_0.html">version 3.15.0</a> (2016-10-14). +New query parameters might be added in the future. +</p> + +<dl> +<a name="uricache"></a> + +<dt><b>cache=shared<br>cache=private</b></dt> +<dd><p>The cache query parameter determines if the new database is opened +using <a href="sharedcache.html">shared cache mode</a> or with a private cache. +</p></dd> + +<a name="uriimmutable"></a> + +<dt><b>immutable=1</b></dt> +<dd><p>The immutable query parameter is a boolean that signals to +SQLite that the underlying database file is held on read-only media +and cannot be modified, even by another process with elevated +privileges. SQLite always opens immutable database files +read-only and it skips all file locking and change detection +on immutable database files. If this query parameter (or +the <a href="c3ref/c_iocap_atomic.html">SQLITE_IOCAP_IMMUTABLE</a> bit in xDeviceCharacteristics) +asserts that a database file is immutable and that file +changes anyhow, then SQLite might return incorrect query +results and/or <a href="rescode.html#corrupt">SQLITE_CORRUPT</a> errors. +</p></dd> + +<a name="urimode"></a> + +<dt><b>mode=ro<br>mode=rw<br>mode=rwc<br>mode=memory</b></dt> +<dd><p>The mode query parameter determines if the new database is opened +read-only, read-write, read-write and created if it does not exist, or +that the database is a pure in-memory database that never interacts with +disk, respectively. +</p></dd> + +<a name="urimodeof"></a> + +<dt><b>modeof=</b><i>filename</i></dt> +<dd><p>When creating a new database file during <a href="c3ref/open.html">sqlite3_open_v2()</a> +on unix systems, SQLite will try to set the permissions of the new +database file to match the existing file "<i>filename</i>". +</p></dd> + +<a name="urinolock"></a> + +<dt><b>nolock=1</b></dt> +<dd><p>The nolock query parameter is a boolean that disables all calls +to the xLock, xUnlock, and xCheckReservedLock methods of the VFS when true. +The nolock query parameter might be used, for example, when trying to +access a file on a filesystem that does not support file locking. +Caution: If two or more <a href="c3ref/sqlite3.html">database connections</a> try to interact with +the same SQLite database and one or more of those connections has +enabled "nolock", then database corruption can result. The "nolock" +query parameter should only be used if the application can guarantee +that writes to the database are serialized. + +<a name="uripsow"></a> + +</p></dd><dt><b>psow=0<br>psow=1</b></dt> +<dd><p>The psow query parameter overrides the <a href="psow.html">powersafe overwrite</a> +property of the database file being opened. The psow query parameter +works with the default windows and unix <a href="vfs.html">VFSes</a> but might be a no-op for +other proprietary or non-standard VFSes. +</p></dd> + +<a name="urivfs"></a> + +<dt><b>vfs=</b><i>NAME</i></dt> +<dd><p>The vfs query parameter causes the database connection to be opened +using the <a href="vfs.html">VFS</a> called <i>NAME</i>. +The open attempt fails if <i>NAME</i> is not the name of a <a href="vfs.html">VFS</a> that +is built into SQLite or that has been previously registered using +<a href="c3ref/vfs_find.html">sqlite3_vfs_register()</a>.</p></dd> +</dl> + +<h1 id="see_also"><span>4. </span>See Also</h1> + +<ul> +<li> <a href="c3ref/open.html#urifilenamesinsqlite3open">URI filenames in sqlite3_open()</a> +</li><li> <a href="c3ref/open.html#urifilenameexamples">URI filename examples</a> +</li></ul> +<p align="center"><small><i>This page last modified on <a href="https://sqlite.org/docsrc/honeypot" id="mtimelink" data-href="https://sqlite.org/docsrc/finfo/pages/uri.in?m=adfa05577ead37cf9">2022-01-20 21:38:08</a> UTC </small></i></p> + |