D_KEYEXIST

SUMMARY
   d_keyexist(FIELD[,dbn])
   long FIELD;
   int dbn;

ARGUMENTS
   FIELD       The field type of the optional key field the existence of which
               is to be checked.

   dbn         (optional) The number of the database containing the record.

DESCRIPTION
   This function determines if the key for optional key FIELD in the current
   record has been stored.Status S_OKAY is returned if the key has been stored.
   Status S_NOTFOUND is returned if the key has not been stored.
   This function reads the optional key bit from the record header stored in
   the data file. Thus ,in shared access mode,the data file must be locked.

CURRENCY CHANGES
   None.

RETURN CODES

   0     S_OKAY         optional key value has been stored.

   2     S_NOTFOUND     Optional key value not stored.

  -5     S_INVFLD       Invalid field type.

   -24   S_NOTLOCKED    Data file containing current record is not locked.

   -37   S_NOTOPTKEY    Specified field type is not defined as an optional key.

   -38   S_BADFIELD     Specified field type not defined in current record.


EXAMPLE

    if (d_keyexist(EMP_ID)==S_NOTFOUND)
     {
      /* store employee id  */
     d_keystore(EMP_ID);
     }