MySQL Time Zone Tables

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Revision as of 21:23, 26 November 2012 by R5gordini (Talk | contribs)

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Starting with MythTV version 0.26, the time zone tables must be loaded in MySQL. This should be done before attempting the upgrade. mythtv-setup and mythbackend will not start without the tables loaded and an error message will apppear in the respective log explaining that.

This is important for users building from source, users loading MythTV from a package, for example Mythbuntu, should expect the tables to be loaded automatically.

To see if the tables are already loaded, enter mysql and type:

SELECT CONVERT_TZ('2012-06-07 12:00:00', 'GMT', 'America/New_York');

If the response looks like:

+--------------------------------------------------------------+
| CONVERT_TZ('2012-06-07 12:00:00', 'GMT', 'America/New_York') |
+--------------------------------------------------------------+
| 2012-06-07 08:00:00                                          |
+--------------------------------------------------------------+

the tables are loaded and no further action is required.

Important.png Note: If the time zone tables are updated, then the procedure below should be repeated.

If the response looks like:

+--------------------------------------------------------------+
| CONVERT_TZ('2012-06-07 12:00:00', 'GMT', 'America/New_York') |
+--------------------------------------------------------------+
| NULL                                                         |
+--------------------------------------------------------------+

then the tables must be loaded.

Assuming the distribution's time zone information is in /usr/share/zoneinfo, type:

mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p<yourpassword> mysql

Remove the -p<yourpassword> from the above if you don't have one.

Restart MySQL, and repeat the initial test.

It appears that some distributions do not contain info for the UTC time zone, which seems to be the timezone that mythbackend and mythtv-setup check for before starting. Some distributions may have something called Etc/UTC, but not UTC!

This can be added manually by executing the following:

> mysql -u root -p mysql
INSERT INTO time_zone (Use_leap_seconds) VALUES ('N');
SET @time_zone_id= LAST_INSERT_ID();
INSERT INTO time_zone_name (Name, Time_zone_id) VALUES ('UTC', @time_zone_id);
INSERT INTO time_zone_transition_type (Time_zone_id, Transition_type_id, Offset, Is_DST, Abbreviation) VALUES
(@time_zone_id, 0, 0, 0, 'UTC');
ALTER TABLE time_zone_transition ORDER BY Time_zone_id, Transition_time;
ALTER TABLE time_zone_transition_type ORDER BY Time_zone_id, Transition_type_id;

WARNING - this fix is currently unsupported and untested!

References: