When insert_record is called and it doesn't find any columns
to insert data into, that is a dml_exception as you need at least
one column in the database to insert into it. This can happen
when you have created a zero column database table, or the table
does not exist.
Includes following fixes:
* support for MS SQL Server
* optional trimming of of oversized VARCHAR fields
* conversion to forms library
* full localisation
* other cleanup
List of changes:
* New OOP API using PHP namespace \core\session\.
* All handlers now update the sessions table consistently.
* Experimental DB session support in Oracle.
* Full support for session file handler (filesystem locking required).
* New option for alternative session directory.
* Official memcached session handler support.
* Workaround for memcached version with non-functional gc.
* Improved security - forced session id regeneration.
* Improved compatibility with recent PHP releases.
* Fixed borked CSS during install in debug mode.
* Switched to file based sessions in new installs.
* DB session setting disappears if DB does not support sessions.
* DB session setting disappears if session handler specified in config.php.
* Fast purging of sessions used in request only.
* No legacy distinction - file, database and memcached support the same functionality.
* Session handler name included in performance info.
* Fixed user_loggedin and user_loggedout event triggering.
* Other minor bugfixing and improvements.
* Fixed database session segfault if MUC disposed before $DB.
Limitations:
* Session access time is now updated right after session start.
* Support for $CFG->sessionlockloggedinonly was removed.
* First request does not update userid in sessions table.
* The timeouts may break badly if server hosting forces PHP.ini session settings.
* The session GC is a lot slower, we do not rely on external session timeouts.
* There cannot be any hooks triggered at the session write time.
* File and memcached handlers do not support session lock acquire timeouts.
* Some low level PHP session functions can not be used directly in Moodle code.
This is necessary because MySQL get_recordset_sql() stores the data in memory, unfortunately the alternative resultset iteration blocks concurrent access - that is why we need new method for export.
Includes:
* constants refactoring
* reworked db table init
* support for $CFG->debug = -1
* functional DB tests
* fixed $DB->get_indexes() to not throw exceptions when table does not exist
* fix handling of user passwords in test db
* add debug info to exception messages
* removed unnecessary PHP debug errors from mathslib
* fixed @error suppression in get_string
* fixed PHPUnit error handler setup
* added timezone info to default install
