Editing EPrints and MariaDB 10 (section)

== Not Null without Default Value ==
In EPrints a MetaField can set the attribute <tt>allow_null => 0</tt>.  This means strictly it has has to have a default value.  Prior to EPrints 3.4.4, default values were not set for MetaFields created with <tt>allow_null => 0</tt> and not [https://github.com/eprints/eprints3.4/issues/196 until EPrints 3.4.5] were the default values tailored depending on the type of database field.  [[EPrints_and_MySQL_8 | MySQL 8]] also has the same issue.

If you are running an earlier version of EPrints, you could manually alter your database to make sure any MetaField that have <tt>allow_null => 0</tt> and set a default value something like:
 ALTER TABLE `eprint` MODIFY COLUMN `not_null_field` VARCHAR(255) NOT NULL DEFAULT '';
Otherwise, you could change your MySQL server's configuration to overlook this by adding the following to <tt>/etc/mysql/mysql.conf.d/mysqld.cnf</tt> (and affectively removing the part of <tt>STRICT_TRANS_TABLES</tt> that causes this to error).  Once done remember to restart MySQL:
 sql_mode=ONLY_FULL_GROUP_BY,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION