DataView knows two table formats - the DataView format and the foreign format. As a rule you will map all objects in the DataView table format. Entities, however, can also be mapped in foreign format tables. This can be necessary if you have to integrate existing data stock with a fixed table format into an application or if connected external applications do not support the DataView table format. The table format is selected in the field mapping type of the entity form.
Irrespective of the model object to be mapped, a DataView table contains columns to store internal system attributes in addition to columns to store object-specific attributes.
DataView automatically assigns the system attributes when records are entered into the table. The most important internal system attribute is the Ident number (C_ID). The C_ID forms the unique key to identify each record. It has digits and is created by DataView using a random number generator. In relation- and type tables additional internal Ident numbers (C_ID_1, C_ID_2) point to the connected parent- or child records. The additional internal system attributes are responsible for automatic locking, access control and dating.
You can use [Ctrl+A] to display important internal system fields in all created application masks to check them.
Foreign format tables do not contain columns for internal system attributes. Thus records in foreign format tables cannot be identified by the automatic assignment of internal Ident numbers. You must manually select at least one suitable key field from the set of object-specific attribute fields in order to be able to uniquely identify records (e.g. a number field). Key fields are marked in the foreign key flag F of the table-field assignment. The flag is only visible if you create fields for a master table in the foreign format. You can use several fields in a combined key. Foreign key fields should be indexed, be set to unique and created as non-zero fields.
For foreign format tables, relations to other database tables (whether these are DataView- or foreign format tables) must be created with the help of links. The locking- and access protection guaranteed in DataView tables can only be realized for foreign format tables by creating individual userexits for this purpose. Additionally, it is not possible to delete records temporarily in foreign format tables.