Compiling with just the CREATEXFD directive

You can compile the preceding program with just the CREATEXFD directive to generate the XFD. The compiled program will run and will build the database table shown at the end of this section.

Here's how the database table is built. First, any fields listed in the KEY IS clause of the SELECT are included ("p-o-number" in this example). Then the Compiler takes the largest record ("p-o-detail-record") and lists the fields that make up that record. The rest of this section shows the specific fields that are placed into the table.

All of the data from the COBOL program is stored in and retrieved from the database, even though not all fields are explicitly named in the database table. For a description of how this works, see the chapter XFDs.

The underlined fields are the only ones that will be entered into the table:

fd p-o-file.
 01  p-o-record.
     03  p-o-division-number                   pic 9(3).
     03  p-o-record-type                       pic x.
         88  header-record                     value "h".
         88  detail-record                     value "d".
     03  p-o-number                            pic 9(10).
     03  p-o-number-detail redefines p-o-number.
         05  picking-ticket-number             pic 9(6).
         05  shipping-region                   pic 9(2).
         05  p-o-customer-type                 pic 9(2).
         05  p-o-customer-breakdown redefines 
               p-o-customer-type.
             07  customer-category             pic x.
                 88  p-o-customer-retail       value "r".
                 88  p-o-customer-whlsale      value "w".
             07  customer-pay-format           pic x.
                 88 is-net-30                  value "3".
                 88 is-net-10                  value "1".
     03  p-o-date.
         05  p-o-yy                            pic 9(2).
         05  p-o-mm                            pic 9(2).
         05  p-o-dd                            pic 9(2).
 
 01  p-o-detail-record.
     03  p-o-dept-number                       pic 9(3).
     03  p-o-record-type                       pic x.
     03  detail-p-o-number                     pic 9(10).
     03  p-o-shipping-info.
         05  p-o-quantity-to-ship              pic s9(4) comp.
         05  p-o-total-quantity                pic s9(4) comp.
     03  p-o-notes.
         05  notes-line occurs 3 times         pic x(40).

As the table is built:

Any hyphens in the COBOL field names are converted to underscores
Field names longer than 18 characters will cause a warning to be issued if they are not unique within the first 18 characters. Some databases limit you to 18 total characters. We recommend that for portability and for end-user purposes you use the least number of characters. You can use the NAME XFD directive for this to avoid changing your procedure division code
Fields in OCCURS clauses get special handling, because the run-time system must assign a unique name to each data item, so sequential index numbers are appended to the item named in the OCCURS. Limits vary between databases, so refer to the documentation that accompanied your RDBMS. In some instances, the name may be truncated by the Connector if necessary before the index is added

Note: detail-p-o-number is not part of the table because the key overlays this area.

The following table is built in the database:

Column Name	Type
p_o_number	number(10)*
p_o_dept_number	number(3)*
p_o_record_type	char(1)
p_o_quantity_to_ship	number(4)*
p_o_total_quantity	number(4)*
notes_line_1	char(40)
notes_line_2	char(40)
notes_line_3	char(40)

* The actual database datatype may vary.

For a list of supported data types and their COBOL equivalents, see the Limits and Ranges section found in the appendix of this manual that is specific to your RDBMS.