SQLite3 support in freepbx
--------------------------

If you are reading this, you should be aware that the support for sqlite3 is not 
perfect at the writing of this document. Many things are garanteed not to work, and 
patches are more then welcome.

This document speaks about SQLite3 on Debian Etch (version 3.3.8 or above), and not other versions. 
SQLite2 is deprecated, since it contains a lot of unsupported syntax (or does not support some mysql 
extensions widly used in freepbx)


1) Creating the initial tables
------------------------------
The first step will be creating a default "database" for freepbx to use. We cannot use the 
standard newinstall.sql file, because of these reasons:

a) Syntax for auto_increment is (for example)
	  `id` integer NOT NULL PRIMARY KEY AUTOINCREMENT
   ALL OTHER FORMS WILL NOT WORK. Note that this code is supported
   by php5, but php4 does not like AUTOINCREMENT since it uses AUTO_INCREMENT.
   Look at the install.php of the freePBX modules to see a work-around.
b) Only  one primary key per table is supported
c) ALTER is not supported (really? I am not sure)
d) SUBSTRING is not supported
e) enums are not supported

There is a special sql file for sqlite3, which should be identical to the 
standard file for mysql, execept of this changes:

1) some tables use string instead of enums
2) all integers are "int"
3) strings are "varchar" and not other types


To create the initial DB run this command:
	cat newinstall.sqlite.sql | sqlite3 /var/lib/asterisk/freepbx.db


2) Configuring freepbx to use sqlite3 instead of mysql
------------------------------------------------------
You will need to add 2 new entries in /etc/amportal.conf:

	AMPDBENGINE=sqlite3
	AMPDBFILE=/var/lib/asterisk/freepbx.db

These new entries, will cause the following entries to be obsolete (you can safely remove them from amportal.conf/freepbx.conf):
	AMPDBHOST
	AMPDBUSER
	AMPDBPASS
	
That's it. Be sure that apache (or whatever web server you are using) has
write access to the sqlite3 databse file. Usually, these commands will be enough:

	chown www-data.www-data /var/lib/asterisk/freepbx.db
	chmod g+rw /var/lib/freepbx/freepbx.db

You also must confirm that the web server has write access to the library
as well:
	chown www-data.www-data /var/lib/asterisk/
	chmod g+rw /var/lib/asterisk/

(Trixbox generally uses "asterisk" as the user for apache, so no special work is needed
but this is will documented here)
	
That's it. freepbx should now work.


3) Moving back from sqlite3 back to mysql
-----------------------------------------
I will not discuss here about importing and exporting the data, since this should
be pretty trivial. 

You need to set AMPDBENGINE=mysql (or remark that line, as the default is to use 
mysql as on AMP). Do not forget to set the variables to define the connection:
	AMPDBHOST
	AMPDBUSER
	AMPDBPASS

	
4) Behind the scenes
--------------------
If you are not interested about how this work is been done, you may ignore the rest 
of this document.

One of the most important changes, is found in amp_conf/htdocs/admin/common/db_connect.php, were
the creation of the database handle is created. If you are adding support for new connections
this should be the first please to start coding.

There are some queries which use unsupported features as well. Some can be found at 
amp_conf/htdocs/admin/modules/core/functions.inc.php, core_trunks_list(). Special cases
have been made, and the code has been fixed in PHP (istead of SQL)


5) TODO
-------
a) as always, test, test, test....

6) Contact
----------
If you have more questions, feel free to contact me, or post a message on the amportal-devel 
mailing list.

	amportal-devel@lists.sourceforge.net
	diego.iastrubni@xorcom.com
	
	
Diego