Child records configuration¶

The “children” property is used to create nested structures, generally MM tables where additional information needs to be stored. This will correspond to inline-type (“IRRE”) fields with MM tables having a primary key field (“uid”).

See the Mapping data chapter for an overview of import scenarios which may help understand this feature.

Example:

          $GLOBALS['TCA']['tx_externalimporttest_product']['columns']['pictures']['external'] = [
   'base' => [
       ...
       'children' => [
               'table' => 'sys_file_reference',
               'columns' => [
                       'uid_local' => [
                               'field' => 'pictures'
                       ],
                       'uid_foreign' => [
                               'field' => '__parent.id__'
                       ],
                       'title' => [
                               'field' => 'picture_title'
                       ],
                       'tablenames' => [
                               'value' => 'tx_externalimporttest_product'
                       ],
                       'fieldname' => [
                               'value' => 'pictures'
                       ],
                       'table_local' => [
                               'value' => 'sys_file'
                       ]
               ],
               'controlColumnsForUpdate' => 'uid_local, uid_foreign, tablenames, fieldname, table_local',
               'controlColumnsForDelete' => 'uid_foreign, tablenames, fieldname, table_local',
       ]
       ...
   ]
]

Properties¶

Property	Data type	Step/Scope
table	string	Store data
columns	array	Store data
controlColumnsForUpdate	string	Store data
controlColumnsForDelete	string	Store data
disabledOperations	string	Store data

table¶

Type: string
Description: Name of the nested table. This information is mandatory.
Scope: Store data

columns¶

Type

array

Description

List of columns (database fields) needed for the nested table. This is an associative array, using the column name as the key. Then each column must have one of two properties

value

This is a simple value that will be used for each entry into the nested table. Use it for invariants like the “tablenames” field of a MM table.

field

This is the name of a field that is available in the imported data. The value is copied from the current record. Note that such fields can be any of the mapped columns, any of the additionalFields or any of the substructureFields.

The special value __parent.id__ refers to the primary key of the current record and will typically be used for “uid_local” or “uid_foreign” fields in MM tables, depending on how the relation is built.

Scope

Store data

controlColumnsForUpdate¶

Type

string

Description

Comma-separated list of columns that need to be used for checking if a child record already exists. All these columns must exist in the list of columns defined above. Defining this property ensures that existing relations are updated instead of being created anew.

This list should contain all columns that are significant for identifying a child record without ambiguity. In the example above, we have:

'controlColumnsForUpdate' => 'uid_local, uid_foreign, tablenames, fieldname, table_local',

These are all the columns that need to be queried in the “sys_file_reference” table to be sure that we are targeting the right record in the database. Any missing information might mean retrieving another record (for a different table or field, or whatever).

Note

If this property is not defined, all children records will be considered to be new. If controlColumnsForDelete is defined and the “delete” operation is not disabled, all existing child relations will be deleted upon each import.

Scope

Store data

controlColumnsForDelete¶

Type: string
Description: This is similar to controlColumnsForUpdate but for finding out which existing relations are no longer relevant and need to be deleted. It is not the same list of fields as you need to leave out the field which references the relation on the “other side”. In the case of “sys_file_reference”, you would leave out “uid_local”, which is the reference to the “sys_file” table.

Note

If this property is not defined, existing children records will not be checked and thus never be deleted.
Scope: Store data

disabledOperations¶

Type: string
Description: Comma-separated list of operations which should not take place. This can be “insert” (no new child records), “update” (no update to existing child records) and/or “delete” (no removal of existing child records).

Note

This applies only when a parent record is being updated. When a parent record is being created, it does not make sense to forbid creation of its child records.
Scope: Store data