= Trac and SQLAlchemy

Trac works with the [http://www.sqlalchemy.org/ SQLAlchemy] database wrapper. Instructions for installing and using SQLAlchemy are listed at th:SqlAlchemyQueryMacro.

== List of things to do

 1. trac/db/*backend.py files should ultimately be collapsed into one backend.py file
 1. trac/upgrades/db*.py files need upgrading to SQLAlchemy
 1. database schema needs a review, see MySQL fault later on the page
 1. database schema needs relations setup and especially separating out a 'user' table, helps with user provider architecture, eg LDAP

== Tables

The current database schema has deficiencies.

 * system table
 * permission table
 * auth_cookie table
 * session table
 * session_attribute table
 * attachment table: id is text, for ticket type it is a number, for wiki it is an unique text identifier
 * wiki table
 * revision table
 * node_change table
 * ticket table
 * ticket_change table
 * ticket_custom table
 * enum table
 * component table
 * milestone table
 * version table
 * report table

== Known issues

When Trac is installed with MySQL, the initialization fails with:
{{{
OperationalError: (OperationalError) (1170, "BLOB/TEXT column 'rev' used in key
specification without a key length") 'CREATE TABLE node_change (rev TEXT NOT NULL,
path TEXT NOT NULL, node_type VARCHAR(1), change_type VARCHAR(1) NOT NULL,
base_path TEXT, base_rev TEXT, PRIMARY KEY (rev, path, change_type))' {}
}}}