Using XFD Directives

XFDs may be built directly from your source code with only the -Fx option if the compiler's default mapping rules are sufficient for your situation. If you would like to override the default mapping behavior or map a field to a different name, you can add additional directives to your COBOL code.

These directives are optional comments that you can place into an FD in your COBOL source code to control how XFDs are built. By controlling how XFDs are built, you can guide the way AcuXDBC will map the content of your COBOL files' fields to columns in the tables that comprise your database.

Among other things, directives enable you to

Specify a column name to be used in place of a COBOL field name
Map elementary items of a group item together into a single column
Cause the fields from a specific record in a file to appear in the database table (rather than just the fields from the largest record)
Give a name to the XFD file itself

Directives are always placed within a COBOL FD. They do not affect Procedure Division I/O statements, and they do not change your COBOL data in any way. The only exception to this is the CREATEXFD directive, which must be placed before the first COBOL SELECT statement.

Note: If you are going to access your COBOL data from an ODBC- or JDBC-enabled application, each field in the application must correspond to a data item in your COBOL FD or XFD. To ensure that this is the case, you may need to use the NAME directive to add fields to the XFD.