Additional considerations for describing display files that contain DBCS data

Be aware of these additional considerations when you describe display files that contain DBCS data.

• Specify IGCDTA(*YES) on the CRTDSPF command when DBCS data is present in the file, but not indicated in DDS. For example, specify IGCDTA(*YES) if the file sends messages that are DBCS (DDS keyword MSGCON).
• Prevent users from using display files to insert alphanumeric data into DBCS database files by specifying the keyboard shift for a field in a field reference file rather than in a display file. Users cannot type alphanumeric data in input-capable fields of DBCS display files and, therefore, cannot type alphanumeric data into the database file.

  Specify data type J or G in a database field reference file and R in position 29 of the associated display file.

  Use data type J or G for all fields in a field reference file to reduce the possibility of incorrectly setting the default keyboard shift to O (open).

• Describe fields in the file as DBCS fields to cause the system to consider the file to be DBCS even if you do not specify IGCDTA(*YES) on the CRTDSPF command.
• The system displays the DBCS data that does not fit on one display line onto the next display line with the following effects:
  • DDS sends a warning message stating that it split DBCS characters for constant and initialized fields containing DBCS data.
  • DDS sends a warning message stating that it split DBCS characters if you specified the J, E, or G data type.
  • DDS does not send a warning message stating that it split DBCS characters if you specified the O data type. DDS warns you of the potential for this problem when the file is created.
  • The second display line of a continued field might not make sense if the system must split a DBCS character in order to continue the line.
• Text with bracketed-DBCS characters can be used anywhere that comments and character strings are allowed.
• Consider the following rules when you specify subfiles:
  • Use the SFLMSG keyword to create DBCS messages by typing DBCS data for the character string in the message.

    Check the length of the message. The space available to display it must be long enough to contain the message. DDS warns you when a display field might be truncated. However, the field might be truncated in the middle of a DBCS character, and the data displayed following the truncated character will not make sense.

  • The system ignores the SFLEND keyword when displaying a plus sign (+) to indicate that more records exist in the subfile. When displaying the plus sign, the system writes over a DBCS character.
• Consider the following rules when you specify the MSGID keyword:
  • If the message text contains DBCS characters, and the message length exceeds the MSGID field length, the message text is truncated so that it ends with an alphanumeric character. If the truncation occurs in the middle of a DBCS character, the text truncates after the previous DBCS character and a shift-in character is added to the end of the text.
  • If the message text contains DBCS characters, either define the MSGID field so that it does not wrap to the next line, or make sure the message text does not wrap in the middle of a DBCS character.