249 lines
9.0 KiB
HTML
249 lines
9.0 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>The Schema Table</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>
|
|
<div class=fancy>
|
|
<div class=nosearch>
|
|
<div class="fancy_title">
|
|
The Schema Table
|
|
</div>
|
|
<div class="fancy_toc">
|
|
<a onclick="toggle_toc()">
|
|
<span class="fancy_toc_mark" id="toc_mk">►</span>
|
|
Table Of Contents
|
|
</a>
|
|
<div id="toc_sub"><div class="fancy-toc1"><a href="#introduction">1. Introduction</a></div>
|
|
<div class="fancy-toc1"><a href="#alternative_names">2. Alternative Names</a></div>
|
|
<div class="fancy-toc1"><a href="#interpretation_of_the_schema_table">3. Interpretation Of The Schema Table</a></div>
|
|
</div>
|
|
</div>
|
|
<script>
|
|
function toggle_toc(){
|
|
var sub = document.getElementById("toc_sub")
|
|
var mk = document.getElementById("toc_mk")
|
|
if( sub.style.display!="block" ){
|
|
sub.style.display = "block";
|
|
mk.innerHTML = "▼";
|
|
} else {
|
|
sub.style.display = "none";
|
|
mk.innerHTML = "►";
|
|
}
|
|
}
|
|
</script>
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
<h1 id="introduction"><span>1. </span>Introduction</h1>
|
|
|
|
<p>Every SQLite database contains a single "schema table" that stores the
|
|
schema for that database. The schema for a database is a description of
|
|
all of the other tables, indexes, triggers, and views that are
|
|
contained within the database. The schema table looks like this:
|
|
|
|
</p><blockquote><pre>
|
|
CREATE TABLE sqlite_schema(
|
|
type text,
|
|
name text,
|
|
tbl_name text,
|
|
rootpage integer,
|
|
sql text
|
|
);
|
|
</pre></blockquote>
|
|
|
|
<p>The sqlite_schema table contains one row for each table, index, view,
|
|
and trigger (collectively "objects") in the schema, except there
|
|
is no entry for the sqlite_schema table itself. See the
|
|
<a href="fileformat2.html#ffschema">schema storage</a> subsection of the <a href="fileformat2.html">file format</a> documentation for
|
|
additional information on how SQLite uses the sqlite_schema table
|
|
internally.
|
|
|
|
</p><h1 id="alternative_names"><span>2. </span>Alternative Names</h1>
|
|
|
|
<p>The schema table can always be referenced using the name "sqlite_schema",
|
|
especially if qualifed by the schema name like
|
|
"main.sqlite_schema" or "temp.sqlite_schema". But for historical
|
|
compatibility, some alternative names are also recognized, including:
|
|
|
|
</p><ol>
|
|
<li> sqlite_master
|
|
</li><li> sqlite_temp_schema
|
|
</li><li> sqlite_temp_master
|
|
</li></ol>
|
|
|
|
<p>
|
|
Alternatives (2) and (3) only work for the TEMP database associated
|
|
with each database connection, but alternative (1) works anywhere.
|
|
For historical reasons, callbacks from the <a href="c3ref/set_authorizer.html">sqlite3_set_authorizer()</a>
|
|
interface always refer to the schema table using names (1) or (3).
|
|
|
|
</p><h1 id="interpretation_of_the_schema_table"><span>3. </span>Interpretation Of The Schema Table</h1>
|
|
|
|
<p>The meanings of the fields of the schema table are as follows:
|
|
|
|
</p><dl>
|
|
<dt><b>type</b></dt>
|
|
<dd>
|
|
<p>The sqlite_schema.type column will be one
|
|
of the following text strings: 'table', 'index', 'view', or 'trigger'
|
|
according to the type of object defined. The 'table' string is used
|
|
for both ordinary and <a href="vtab.html">virtual tables</a>.</p>
|
|
</dd>
|
|
|
|
<dt><b>name</b></dt><dt>
|
|
</dt><dd>
|
|
<p>The sqlite_schema.name column will hold the name of the object.
|
|
(<a href="lang_createtable.html#uniqueconst">UNIQUE</a> and <a href="lang_createtable.html#primkeyconst">PRIMARY KEY</a> constraints on tables cause SQLite to create
|
|
<a href="fileformat2.html#intschema">internal indexes</a> with names of the form "sqlite_autoindex_TABLE_N"
|
|
where TABLE is replaced by the name of the table that contains the
|
|
constraint and N is an integer beginning with 1 and increasing by one
|
|
with each constraint seen in the table definition.
|
|
In a <a href="withoutrowid.html">WITHOUT ROWID</a> table, there is no sqlite_schema entry for the
|
|
PRIMARY KEY, but the "sqlite_autoindex_TABLE_N" name is set aside
|
|
for the PRIMARY KEY as if the sqlite_schema entry did exist. This
|
|
will affect the numbering of subsequent UNIQUE constraints.
|
|
The "sqlite_autoindex_TABLE_N" name is never allocated for an
|
|
<a href="lang_createtable.html#rowid">INTEGER PRIMARY KEY</a>, either in rowid tables or WITHOUT ROWID tables.
|
|
</p>
|
|
</dd>
|
|
|
|
<dt><b>tbl_name</b></dt>
|
|
<dd>
|
|
<p>The sqlite_schema.tbl_name column holds the name of a table or view
|
|
that the object is associated with. For a table or view, the
|
|
tbl_name column is a copy of the name column. For an index, the tbl_name
|
|
is the name of the table that is indexed. For a trigger, the tbl_name
|
|
column stores the name of the table or view that causes the trigger
|
|
to fire.</p>
|
|
</dd>
|
|
|
|
<dt><b>rootpage</b></dt>
|
|
<dd>
|
|
<p>The sqlite_schema.rootpage column stores the page number of the root
|
|
b-tree page for tables and indexes. For rows that define views, triggers,
|
|
and virtual tables, the rootpage column is 0 or NULL.</p>
|
|
</dd>
|
|
|
|
<dt><b>sql</b></dt>
|
|
<dd>
|
|
<p>The sqlite_schema.sql column stores SQL text that describes the
|
|
object. This SQL text is a <a href="lang_createtable.html">CREATE TABLE</a>, <a href="lang_createvtab.html">CREATE VIRTUAL TABLE</a>,
|
|
<a href="lang_createindex.html">CREATE INDEX</a>,
|
|
<a href="lang_createview.html">CREATE VIEW</a>, or <a href="lang_createtrigger.html">CREATE TRIGGER</a> statement that if evaluated against
|
|
the database file when it is the main database of a <a href="c3ref/sqlite3.html">database connection</a>
|
|
would recreate the object. The text is usually a copy of the original
|
|
statement used to create the object but with normalizations applied so
|
|
that the text conforms to the following rules:
|
|
|
|
</p><ul>
|
|
<li>The CREATE, TABLE, VIEW, TRIGGER, and INDEX keywords at the beginning
|
|
of the statement are converted to all upper case letters.
|
|
</li><li>The TEMP or TEMPORARY keyword is removed if it occurs after the
|
|
initial CREATE keyword.
|
|
</li><li>Any database name qualifier that occurs prior to the name of the
|
|
object being created is removed.
|
|
</li><li>Leading spaces are removed.
|
|
</li><li>All spaces following the first two keywords are converted into a single
|
|
space.
|
|
</li></ul>
|
|
|
|
<p>The text in the sqlite_schema.sql column is a copy of the original
|
|
CREATE statement text that created the object, except normalized as
|
|
described above and as modified by subsequent <a href="lang_altertable.html">ALTER TABLE</a> statements.
|
|
The sqlite_schema.sql is NULL for the <a href="fileformat2.html#intschema">internal indexes</a> that are
|
|
automatically created by <a href="lang_createtable.html#uniqueconst">UNIQUE</a> or <a href="lang_createtable.html#primkeyconst">PRIMARY KEY</a> constraints.</p>
|
|
</dd>
|
|
</dl>
|
|
|