Documentation Source Text

<h3>4.1 Dependencies</h3>

<p>The build process makes extensive use of the 
[http://www.tcl-lang.org/|Tcl] scripting language.  You will need to have a
copy of TCL installed in order for the make targets above to work.
Easy-to-use installers can be obtained from [http://www.tcl-lang.org/].
Many unix workstations have Tcl installed by default.

<p>The build process also uses [http://en.wikipedia.org/wiki/AWK|AWK].
AWK is almost always installed by default on unix-like workstations,
but it may need to be downloaded and installed on Windows development
platforms.  There are many versions of AWK available for Windows.
Use a search engine to find one.

<p>
^In SQLite, table rows normally have a 64-bit signed integer [ROWID]
which is unique among all rows in the same table.
([WITHOUT ROWID] tables are the exception.)
</p>

<p>
^(You can access the ROWID of an SQLite table using one of the special column
names ROWID, _ROWID_, or OID.
Except if you declare an ordinary table column to use one of those special
names, then the use of that name will refer to the declared column not
to the internal ROWID.)^
</p>

<p>

  This document describes the SQL language that is understood by
  SQLite.  
}
doc {Pragma commands} {pragma.html} {
  This document describes SQLite performance tuning options and other 
  special purpose database commands.
}
doc {Core SQL Functions} {lang_corefunc.html} {
  General-purpose built-in scalar SQL functions.
}
doc {Aggregate SQL Functions} {lang_aggfunc.html} {
  General-purpose built-in aggregate SQL functions.
}
doc {Date and Time SQL Functions} {lang_datefunc.html} {
  SQL functions for manipulating dates and times.
}
doc {JSON SQL Functions} {json1.html} {
  SQL functions for creating, parsing, and querying JSON content.
}
doc {DataTypes} {datatype3.html} {
  SQLite version 3 introduces the concept of manifest typing, where the
  type of a value is associated with the value itself, not the column that
  it is stored in.
  This page describes data typing for SQLite version 3 in further detail.
}

values. 
A varint is between 1 and 9 bytes in length.  The varint consists of either
zero or more byte which have the high-order bit set followed by a single byte
with the high-order bit clear, or nine bytes, whichever is shorter.
The lower seven bits of each of the first eight bytes and all 8 bits of
the ninth byte are used to reconstruct the 64-bit twos-complement integer.
Varints are big-endian: bits taken from the earlier byte of the varint
are the more significant than bits taken from the later bytes. </p>

<p>The format of a cell depends on which kind of b-tree page the cell
appears on.  The following table shows the elements of a cell, in
order of appearance, for the various b-tree page types.</p>

<blockquote><dl>
<dt><p>Table B-Tree Leaf Cell (header 0x0d):</p></dt>

<title>SQLite Home Page</title>

<table border="0" width="100%">
<tr><td valign="top">

<p>SQLite is a software library that implements a
<a href="selfcontained.html">self-contained</a>, 
<a href="serverless.html">serverless</a>,
<a href="zeroconf.html">zero-configuration</a>,
<a href="transactional.html">transactional</a>
SQL database engine.
SQLite is the [most widely deployed]
database engine in the world.
The source code for SQLite is in the
<a href="copyright.html">public domain</a>.
<a href="about.html">More...</a></p>

<hr style="color: #044a64" height="2">

<h3>Sponsors</h3>
<p>Substantial support for the continuing enhancement and maintenance
of SQLite comes from <a href="consortium.html">SQLite Consortium</a>
members, including:</p>

<a name="consortium_members"></a>
<center>
<table border="0" cellpadding="15">

<tcl>hd_puts {

    <a href="https://www.expensify.com/">\
    <img src="images/foreignlogos/expensify.png" width="225" height="32" \
     alt="expensify.org" border="0">\
    </a></td><td>\
    <a href="https://www.expensify.com/">Expensify</a> - \
    We power the most exciting companies in the world using SQLite. </td></tr>'

  sponsor[5] = '<tr><td align="center">\
    <a href="https://www.facebook.com/">\
    <img src="images/foreignlogos/fb.gif" alt="facebook.com" border="0">\
    </a></td><td>\
    <a href="https://www.facebook.com/">Facebook</a> - \
    Giving people the power to share and make the world \
    more open and connected. </td></tr>'

  count = 6
  while( count>0 ){
    i = Math.floor(Math.random()*6)
    if( sponsor[i]!=null ){
      document.write(sponsor[i])
      sponsor[i] = null
      count--
    }

<p>
Precise numbers are difficult to obtain and so exact rankings
are impossible.  But our best guess is that SQLite is the second
mostly widely deployed software library, after libz.
Some commentators observe that SQLite tends
to be statically linked and thus have multiple instances on
each machine, whereas libz tends to have just
a single instance per machine in the form of a shared library or DLL.
So even though the number of devices containing libz
may be greater than the number of
devices that contain SQLite, the total number of instances per device
<em>might</em> be higher for SQLite and so SQLite <em>might</em>
be the single most widely deployed and used software component.
</p>