This manual is no longer being maintained for TYPO3 versions 11.5 and above. The majority of the content has been migrated to the Extbase or Fluid sections in "TYPO3 Explained".

Using Foreign Data Sources

In real projects many times data from different sources has to be ordered. One target of Extbase is to normalize the access to this data sources and to abstract it from the concrete technical solution. These "foreign" data sources could be tables from the same TYPO3 database or a web service.

Extbase building-up strongly of the rule "Convention over Configuration" (see also the appendix A for this). Foreign database tables rarely correspond with the conventions of Extbase. Therefore the assignment of the class to a given table as well as the assignment of field names to property names of the classes must be configured via PHP. This assignment is also called mapping. The following configuration enables the storage of the object data of a class \MyVendor\MyExtension\Domain\Model\Person in the table tt_address, which is available in most TYPO3 installations.


declare(strict_types = 1);

return [
    \MyVendor\MyExtension\Domain\Model\Person::class => [
        'tableName' => 'tt_address',
        'recordType' => \MyVendor\MyExtension\Domain\Model\Person::class,
        'properties' => [
            'dateOfBirth' => [
                'fieldName' => 'birthday',
            'thoroughfare' => [
                'fieldName' => 'street',

The configuration file must return an array with a configuration for each class that needs to be mapped to a database table. The configuration is quite straight forward. The tableName obviously defines the table the class is mapped to. When using single table inheritance, the type of record can be set via recordType. The properties key defines a set of class properties that should be mapped onto fields that don't comply with the naming convention.


Regard in each case that the field type fits the data type of your property. Additional information you will find in "Preparing the tables of the Domain Objects" above in this chapter.

This configuration causes Extbase to use the table tt_address when reconstructing or persisting of objects of the class \MyVendor\MyExtension\Domain\Model\Person. Thereby the values of the properties dateOfBirth and thoroughfare are stored in the fields birthday and street. If the configuration option tableName is not set, Extbase searches for a table that corresponds to the lower case class name, in our case: tx_myextension_domain_model_person. If for a property there is no mapping defined, the property name, translated in lower case with underscores, is expected as field name. The property name dateOfBirth would result in a field name date_of_birth.