Version 20 (modified by 16 years ago) ( diff ) | ,
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MySQL and the MySQLdb Python bindings for MySQL
work in progress, only the most critical information is there for now
Starting with 0.10 Trac can use MySQL for its DatabaseBackend, but only starting with 0.10.4 will MySQL be fully supported (at least that's the plan). So stick to 0.10.3 for now.
Requirements
MySQL
In order to avoid several issues with unicode and international characters throughout Trac (e.g., international characters turning into question marks with mysterious "Incorrect string value" errors logged), we strongly advise MySQL users to only use databases having the utf8
character set and the utf8_general_ci
collation type. However, changing collation to utf8 makes MySQL fail in 4.1.x and 5.0.x versions on MyISAM table type, because some Trac tables indexes become "too big". This will be (hopefully) addressed in 0.10.4. As a workaround it has been recommended to use InnoDB tables instead of MyISAM where this limitation is absent.
Such databases can be created with the MySQL monitor, like that:
CREATE DATABASE trac DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
XXX: I think the above advice on collations is wrong - using a case-insensitive collation does not sound right, and when I used the above command, the indexing process failed when it came to insert a revision which included changes to files with names differing only in case. Recreating the db using the utf8_bin collation allowed things to work as expected.
See also: #4378, where someone stated the opposite (i.e. that setting the collation mode to utf8_bin was not enough… Maybe this depends on the type of tables used. Anyway, there's a patch on #4378 that should solve that issue in all cases.
utf8_general_ci is required because MySQL-Python uses the collation to figure out if it is being passed binary or text. See bug 1693363
To check character set settings for your database, issue command:
mysql> USE trac; Database changed mysql> SHOW VARIABLES LIKE '%character%'; +--------------------------+-------------------- | Variable_name | Value +--------------------------+-------------------- | character_set_client | cp1251 | character_set_connection | cp1251 | character_set_database | utf8 | character_set_filesystem | binary | character_set_results | cp1251 | character_set_server | utf8 | character_set_system | utf8 | character_sets_dir | C:\DevServer\Instal +--------------------------+-------------------- 8 rows in set (0.00 sec) mysql>
See also #3884.
Usually, you also want to create a user and give this user access to the database created above:
CREATE USER tracuser IDENTIFIED BY 'password'; GRANT ALL ON trac.* TO tracuser;
The connection string will then be:
mysql://tracuser:password@localhost/trac
MySQLdb
The recommended version is MySQL-python 1.2.2.
See http://cheeseshop.python.org/pypi/MySQL-python/1.2.2, which contains links to the .tar.gz source distribution as well as pre-built Windows eggs.
Older versions can be found at the mysql-python sourceforge project:
- MySQL-python 1.2.1_p2 was the previously recommended version
- MySQL-python 1.2.0-3.2.2, MySQL-python 1.2.2b2) were reported to have issues (see #3645).
- MySQL-python-1.2.2b2 was reported to solve an
AttributeError: 'array.array' object has no attribute 'startswith'
error seen when viewing a changeset… These problems ought to be fixed in 1.2.2b3; if they are not, or if you have other issues, please file a bug in the MySQL-python Bug Tracker.
Known Issues
Still Opened
next-dev-1.7.x milestone tickets:
- #13080
- Add [trac] mysql_storage_engine option instead of editting my.cnf
next-major-releases milestone tickets:
- #6986
- MySQL schema changes for performance
- #11206
- Reduce join in query process
- #12390
- Attachment table primary key not unique when migrating from SQLite to MySQL
next-stable-1.6.x milestone tickets:
- #12097
- Add a script to contrib for converting MySQL storage engine
- #12363
- Support ucs2/utf16/utf32 charset and utf16_bin/utf32_bin collation in MySQL
unscheduled milestone tickets:
Typical Problems
- #3182
- Error when adding or viewing a ticket using MySQL
- #3857
- Encoding problem with mysql
- #4017
- initenv problem with MySQL - Access Denied
- #4437
- install error (mysql)
- #4528
- TypeError: unhashable type when installing trac-0.10.3 with mysql
- #5012
- 'module' object has no attribute 'connect'
- #6237
- InterfaceError: (0, '') after idle period with mod_wsgi 1.1/Apache 2.2.3
- #6554
- trac-admin allows to init environment with mysql errors
- #6787
- Trac 0.10.4 - ticket module provider fails in background
- #8279
- IntegrityError when not logged in
- #8552
- Formatted time via SQL command FROM_UNIXTIME fails to replace %*
- #9696
- OperationalError: (2002, "Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (13)")
- #9983
- TypeError: int() argument must be a string or a number
- #10287
- TypeError: unsupported type for timedelta microseconds component: unicode
- #10511
- OperationalError: (1030, 'Got error 28 from storage engine')
- #11727
- Problem with synchronizing svn commits to MySQL database
- #3723
- Problems with database encoding
- #12409
- The $ character must be URL encoded if used as a database password
(corresponding custom query)
Conversion
While a more robust method may be created for 0.10.4 to allow easy conversion from SQLite to MySQL, users have reported success with the following method.