WordPress up to version 3.1 does not work with MySQL sql_mode = TRADITIONAL

[kupokomapa]

Being bitten up several times by this problem. If you use MariaDB as a MySQL server you would notice that their default settings for sql_mode (​http://dev.mysql.com/doc/refman/5.0/en/server-sql-mode.html) is set to NO_ENGINE_SUBSTITUTION,TRADITIONAL
This does not work with many of the SQL queries in WordPress, expecially the ones that insert null values for date columns. So two choices here:

1. is to make the sql_mode less strict byt choosing the optimal value for wordpress (I put this in the construct() method of WP_DB)

mysql_query($this->prepare("SET sql_mode = ;"), $this->dbh);

2. Fix the queries which insert non valid data to table fields (the dates are just one example)

[hakre]

Thanks for reporting the issue. It should be possible for some "hotfix" to add your own db-class that is extending from wp-db so to overwrite the wp-db default constructor.

Anyway, can you provide a patch for your modification for other users who have a similar problem?

[ryan]

See #14978, #8857 and other tickets.