EXTRACT

Short Reference

Syntax

EXTRACT [ header | field_group ].

Effect

This statement links the current content of the fields, which were until then included in the field group header resp. field_group via the statement INSERT , to the extract dataset of the program. If there is no field group specified after EXTRACT, then the field group header is implicitly added.

At the first execution of the EXTRACT-statement of a program, the extract dataset is created and the first line added. After execution of an EXTRACT-statement, it is not allowed to incorporate other fields to the specified field group field_group with the INSERT statement. If you do so, an uncatchable exception will be raised at the next EXTRACT-statement for the same field group.

Notes

• As the field group header is the beginning part and sort key of every field group, it is not allowed to incorporate fields into header after execution of the first EXTRACT statement.
  
• The lines of an extract dataset cannot be explicitly deleted and will be kept alive as long as the internal mode of the program.
  
  
  

Example

This example continues the example under INSERT. If the executable program is linked to a fitting logical data base, the fields of the field groups flight_info and flight_date are attached to the extract dataset during the GET-events.

REPORT demo_extract.

NODES: spfli, sflight.

FIELD-GROUPS: header, flight_info, flight_date.

START-OF-SELECTION.

INSERT: spfli-carrid spfli-connid sflight-fldate
          INTO header,
        spfli-cityfrom spfli-cityto
          INTO flight_info.

GET spfli.
  EXTRACT flight_info.

GET sflight.
  EXTRACT flight_date.

Exceptions

Non-Catchable Exceptions

• Cause: EXTRACT after SORT or LOOP.
  Runtime Error: EXTRACT_AFTER_SORT/LOOP
  
• Cause: Not enough roll memory to create the extracts.
  Runtime Error: EXTRACT_BUFFER_NO_ROLL
  Runtime Error: EXTRACT_NO_ROLL_OLD_KEY
  
• Cause: The occupied lenght of a single field is too large.
  Runtime Error: EXTRACT_FIELD_TOO_LARGE
  
• Cause: Problems at creation of the extract dataset master file.
  Runtime Error: EXTRACT_FILE_PTR_NOT_EMPTY
  Runtime Error: EXTRACT_INIT_DIR_EXTRACT
  Runtime Error: EXTRACT_INIT_FILEMASK_INVALID
  Runtime Error: EXTRACT_INIT_FILEMASK_TOO_LARG
  Runtime Error: EXTRACT_INIT_FN_EXTRACT
  
• Cause: Field group HEADER was modified after extraction of records with EXTRACT.
  Runtime Error: EXTRACT_HEADER_NOT_UNIQUE
  
• Cause: Local data is not allowed in field groups.
  Runtime Error: EXTRACT_INSERT_LOCAL_DATA
  
• Cause: Error when opening the external extract dataset master file.
  Runtime Error: EXTRACT_OPEN_EXTRACTFILE_OPEN
  
• Cause: Total data length of a record to be extracted (inclusive HEADER-fields) is too large.
  Runtime Error: EXTRACT_TOO_LARGE