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Fields are columns of a table. The properties of each field in a table are defined in a field descriptor structure FLDDesc. When a table is created with DbiCreateTable, the table descriptor CRTblDesc points to an array of FLDDesc structures, each of which defines a field in the table.

Physical data types

Physical data types can vary from one data source to another. For example, floating point numbers are stored differently by Paradox, dBASE, and SQL data sources. Physical data types of one data source might not be compatible with the physical data types of other data sources to store the same data.

Logical data types

Logical data types are the generic data types used by BDE. These generic types are made interchangeable between data sources because BDE automatically translates them into the proper physical data types for each target data source.

Automatic field translation

To facilitate cross-database processing, BDE does not require your application to translate data to make it compatible with each different data source. As long as your application uses BDE logical data types, BDE handles the translation to the correct physical format for each target data source. When BDE returns data to your application, it can translate all data types as they are stored by the data source back to the generic logical data types, depending on the translate mode of the cursor, xltNONE or xltFIELD.

BDE's logical data types are compatible with standard C language data types.

You can make the application override the translation mechanism when accessing a table, so that it receives data in the physical format used by the data source.