Feature: #95061 - Auto creation of MM tables from TCA¶
TCA table column fields that define
['config']['MM'] can omit specification of the
intermediate mm table layout in
ext_tables.sql. The TYPO3 database analyzer
takes care of proper schema definition.
This feature has been implemented to simplify developers life and to enable the TYPO3 core to handle those schema details since many extensions tend to specify incomplete or broken mm table schema definitions when dealing with this complex area.
Extensions are strongly encouraged to drop
definitions for those intermediate tables referenced by
TCA table columns. Dropping
these definitions allows the core to adapt and migrate definitions if needed.
Extension developers don't need to deal with
ext_tables.sql definitions of
"mm" tables anymore. The TYPO3 schema analyzer creates the intermediate schema depending
TCA field definition. The schema analyzer tries to apply default specifications
if possible. Single
ext_tables.sql definitions take precedence, though.
In practice, suppose the "local" side of a mm table is defined as such in TCA:
... 'columns' => [ ... 'myField' => [ 'label' => 'myField', 'config' => [ 'type' => 'group', 'foreign_table' => 'tx_myextension_myfield_child', 'MM' => 'tx_myextension_myfield_mm', ] ], ... ], ...
Until now, a schema definition similar to this had to be in place in
CREATE TABLE tx_myextension_myfield_mm ( uid_local int(11) DEFAULT '0' NOT NULL, uid_foreign int(11) DEFAULT '0' NOT NULL, sorting int(11) DEFAULT '0' NOT NULL, KEY uid_local (uid_local), KEY uid_foreign (uid_foreign) );
This section can and should be dropped. Indicators a schema definition is affected by this:
A table column TCA config defines
The "MM" intermediate table has no TCA table definition (!).
ext_tables.sqlspecifies a table with fields
The schema analyzer takes care of further possible fields apart from
uid if necessary, depending on "local" side of the TCA definition.
In general, in case an extension got that definition right up until now, the schema analyzer
should not drop or add any additional fields automatically when removing these sections from
ext_tables.sql. Developers are strongly encouraged to drop affected
ext_tables.sql and to verify the install tool schema migrator acts as
expected. The core takes care of these specifications from now on and may add adaptions or migrations
to streamline further details in the future.