SQLite

3.2.0

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that used to generate VDBE code
** that implements the ALTER TABLE command.
**
** $Id: alter.c,v 1.4 2005/03/19 14:45:49 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.

    sqlite3ValueFree(pVal);
  }

  /* Modify the CREATE TABLE statement. */
  zCol = sqliteStrNDup(pColDef->z, pColDef->n);
  if( zCol ){
    char *zEnd = &zCol[pColDef->n-1];
    while( (zEnd>zCol && *zEnd==';') || isspace(*(unsigned char *)zEnd) ){
      *zEnd-- = '\0';
    }
    sqlite3NestedParse(pParse, 
        "UPDATE %Q.%s SET "
          "sql = substr(sql,0,%d) || ', ' || %Q || substr(sql,%d,length(sql)) "
        "WHERE type = 'table' AND name = %Q", 
      zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,

  sqlite3ChangeCookie(pParse->db, v, iDb);

exit_begin_add_column:
  sqlite3SrcListDelete(pSrc);
  return;
}
#endif  /* SQLITE_ALTER_TABLE */

** If addr<0 then change P3 on the most recently inserted instruction.
*/
void sqlite3VdbeChangeP3(Vdbe *p, int addr, const char *zP3, int n){
  Op *pOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p==0 || p->aOp==0 ){
    if( n==P3_DYNAMIC || n==P3_KEYINFO_HANDOFF ){
      sqliteFree((void*)zP3);
    }
    return;
  }
  if( addr<0 || addr>=p->nOp ){
    addr = p->nOp - 1;
    if( addr<0 ) return;
  }

}


proc chng {date desc} {
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}

chng {2005 March 19 (3.2.0)} {
<li>Added support for ALTER TABLE ADD COLUMN.</li>
}

chng {2005 March 16 (3.1.6)} {
<li>Fix a bug that could cause database corruption when inserting
    record into tables with around 125 columns.</li>
<li>sqlite3_step() is now much more likely to invoke the busy handler
    and less likely to return SQLITE_BUSY.</li>
<li>Fix memory leaks that used to occur after a malloc() failure.</li>

# This script generates the "docs.html" page that describes various
# sources of documentation available for SQLite.
#
set rcsid {$Id: docs.tcl,v 1.11 2005/03/19 14:45:50 drh Exp $}
source common.tcl
header {SQLite Documentation}
puts {
<h2>Available Documentation</h2>
<table width="100%" cellpadding="5">
}

}

doc {Compilation Options} {compile.html} {
  This document describes the compile time options that may be set to 
  modify the default behaviour of the library or omit optional features
  in order to reduce binary size.
}

doc {Backwards Compatibility} {formatchng.html} {
  This document details all of the incompatible changes to the SQLite
  file format that have occurred since version 1.0.0.
}

puts {</table>}
footer $rcsid

#
# Run this Tcl script to generate the formatchng.html file.
#
set rcsid {$Id: formatchng.tcl,v 1.13 2005/03/19 14:45:50 drh Exp $ }
source common.tcl
header {File Format Changes in SQLite}
puts {
<h2>File Format Changes in SQLite</h2>

<p>
Every effort is made to keep SQLite fully backwards compatible from
one release to the next.  Rarely, however, some
enhancements or bug fixes may require a change to
the underlying file format.  When this happens and you
must convert the contents of your
databases into a portable ASCII representation using the old version
of the library then reload the data using the new version of the
library.
</p>

<p>
You can tell if you should reload your databases by comparing the
version numbers of the old and new libraries.  If the first digit
of the version number is different, then a reload of the database will
be required.  If the second digit changes, newer versions of SQLite
will be able to read and write older database files, but older versions
of the library may have difficulty reading or writing newer database
files.
For example, upgrading from
version 2.8.14 to 3.0.0 requires a reload.  Going from
version 3.0.8 to 3.1.0 is backwards compatible but not necessarily
forwards compatible.
</p>

<p>
The following table summarizes the SQLite file format changes that have
occurred since version 1.0.0:
</p>

</tr>
<tr>
  <td valign="top">2.0.8 to 2.1.0</td>
  <td valign="top">2001-Nov-12</td>
  <td>The same basic B-Tree format is used but the details of the 
  index keys were changed in order to provide better query 
  optimization opportunities.  Some of the headers were also changed in order
  to increase the maximum size of a row from 64KB to 24MB.<p>

  This change is an exception to the version number rule described above
  in that it is neither forwards or backwards compatible.  A complete
  reload of the database is required.  This is the only exception.</td>
</tr>
<tr>
  <td valign="top">2.1.7 to 2.2.0</td>
  <td valign="top">2001-Dec-21</td>
  <td>Beginning with version 2.2.0, SQLite no longer builds an index for
  an INTEGER PRIMARY KEY column.  Instead, it uses that column as the actual
  B-Tree key for the main table.<p>Version 2.2.0 and later of the library

  earlier.  The 2.7.6 code will not be able to read the journal file
  and thus will not be able to rollback the incomplete transaction
  to restore the database.</p>
  </td>
</tr>
<tr>
  <td valign="top">2.8.14 to 3.0.0</td>
  <td valign="top">2004-Jun-18</td>
  <td><p>Version 3.0.0 is a major upgrade for SQLite that incorporates
  support for UTF-16, BLOBs, and a more compact encoding that results
  in database files that are typically 25% to 50% smaller.  The new file
  format is very different and is completely incompatible with the
  version 2 file format.</p>
  </td>
</tr>
<tr>
  <td valign="top">3.0.8 to 3.1.0</td>
  <td valign="top">2004-Jan-21</td>
  <td><p>Version 3.1.0 adds support for
  <a href="pragma.html#pragma_auto_vacuum">autovacuum mode</a>.
  Prior versions of SQLite will be able to read and autovacuumed
  database but will not be able to write it.  If autovaccum is disabled
  (which is the default condition)
  then databases are fully forwards and backwards compatible.</p>
  </td>
</tr>
<tr>
  <td valign="top">3.1.6 to 3.2.0</td>
  <td valign="top">2004-Mar-19</td>
  <td><p>Version 3.2.0 adds support for the 
  <a href="lang_altertable.html">ALTER TABLE ADD COLUMN</a>
  command.  A database that has been modified by this command can
  not be read by a version of SQLite prior to 3.1.4.  Running 
  <a href="lang_vacuum.html">VACUUM</a>
  after the ALTER TABLE
  restores the database to a format such that it can be read by earlier
  SQLite versions.</p>
  </td>
</tr>
</table>
</blockquote>

<p>
To perform a database reload, have ready versions of the
<b>sqlite</b> command-line utility for both the old and new
version of SQLite.  Call these two executables "<b>sqlite-old</b>"
and "<b>sqlite-new</b>".  Suppose the name of your old database
is "<b>old.db</b>" and you want to create a new database with
the same information named "<b>new.db</b>".  The command to do
this is as follows:
</p>

<blockquote>
  sqlite-old old.db .dump | sqlite-new new.db
</blockquote>
}
footer $rcsid

proc newsitem {date title text} {
  puts "<h3>$date - $title</h3>"
  regsub -all "\n( *\n)+" $text "</p>\n\n<p>" txt
  puts "<p>$txt</p>"
  puts "<hr width=\"50%\">"
}

newsitem {2005-Mar-19} {Version 3.2.0} {
  Version 3.2.0 adds support for ALTER TABLE ADD COLUMN.  
}

newsitem {2005-Mar-16} {Version 3.1.6} {
  Version 3.1.6 fixes a critical bug that can cause database corruption
  when inserting rows into tables with around 125 columns. This bug was
  introduced in version 3.0.0.  See
  <a href="http://www.sqlite.org/cvstrac/tktview?tn=1163">Ticket #1163</a>
  for additional information.

}
  

puts {
<p align="right"><a href="oldnews.html">Old news...</a></p>
</td></tr></table>
}
footer {$Id: index.tcl,v 1.112 2005/03/19 14:45:50 drh Exp $}

#
# Run this Tcl script to generate the lang-*.html files.
#
set rcsid {$Id: lang.tcl,v 1.87 2005/03/19 14:45:50 drh Exp $}
source common.tcl

if {[llength $argv]>0} {
  set outputdir [lindex $argv 0]
} else {
  set outputdir ""
}

    default value other than NULL.
</ul>

<p>The execution time of the ALTER TABLE command is independent of
the amount of data in the table.  The ALTER TABLE command runs as quickly
on a table with 10 million rows as it does on a table with 1 row.
</p>

<p>After ADD COLUMN has been run on a database, that database will not
be readable by SQLite version 3.1.3 and earlier until the database
is <a href="lang_vacuum.html">VACUUM</a>ed.</p>
}

Section {ATTACH DATABASE} attach

Syntax {sql-statement} {
ATTACH [DATABASE] <database-filename> AS <database-name>
}