Binary fields can hold just about any type of file. When a binary field is opened the file stored in the binary field opens with its associated program.  For example, a binary field could store a word document, when accessed it would open with WORD.  

Binary fields requires either the Local 5 or Client/Server 5 file format.  The datafile must be of a variable length type.  The field size can be a maximum of 2GB.  Field length would therefore be a value between 1 and 2,000,000,000.  Do not use commas in the field definition.  Field size can be important to performance.  Use a field size only as large as needed. A binary field can not exist solo on a view. When creating the binary field a second field must also be created in the datafile.  Is associate field is need by the datafile to help create  structures which are not a part of the binary field.

The binary field is created like any other field and is an available option on variable type files.  Field length is set at time of creation also.  To populate the field with a file the command string of Data -- Utility -- Binary  is used.  This option will offer two directions of storage.

Field to Disk

Disk to Field

The direction of the storage is not an attribute of the binary field.  One binary field can contain a record which is Field to Disk and the next record could be Disk to Field. 

With Disk to Field storage the data already exist in a file on the disk and is pulled into the database. The original file is no longer necessary. The database contains a copy of that file.  If this file is opened and modified the changes will not be saved.  If you wish to have changes saved, code can be written which will write the file to a temp directory and resave it to the binary field.

With Field to Disk, a blank text file or a template file is opened and can be edited.  Useful in situations in which you need to create a file for each record.

Binary fields can be up to 2GB in size for each record. Please understand the type of system requirements to support such a database.  Binary fields are not a solution to poor design or a shortcut for programmers. Please use wisely.