TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)

Appendix A 577
Error Messages
Library Procedure Error Messages
17 MESSAGE No master entry (See below for additional status code
17 message.)
MEANING DBFIND is unable to locate master data set entry (chain
head) for specified detail data set's search item value.
ACTION Appropriate action depends on program design.
17 MESSAGE No entry (See above for additional status code 17
message.)
MEANING DBGET mode 1 has been called to reread an entry, but no
"current record" has been established or a call to DBFIND
has set the current record to 0. DBGET is unable to locate
master data set entry with specified key item value. DBGET
has discovered that selected record is empty (does not
contain an entry) when called with mode 4. DBUPDATE or
DBDELETE was called when the "current record" was not
established or was empty.
ACTION Appropriate action depends on program design.
18 MESSAGE Broken chain
MEANING For DBGET with mode parameter equal to 5 (forward
chained read), the "next entry" on current chain (as
designated by internally maintained forward pointer for
data set) contains backward pointer which does not point
to most recently accessed entry (or zero for first member of
a chain).
For DBGET with mode parameter equal to 6 (backward
chained read), the "next entry" on current chain in a
backward direction (as designated by internally
maintained backward pointer for data set) contains a
forward pointer which does not point to most recently
accessed entry (or zero for last entry in a chain).
This error can occur in DBOPEN access modes 1, 5, and 6
because another user can make database modifications
concurrent with this user's accesses. When this error
occurs, no data is moved to user's stack, although internal
pointers maintained by TurboIMAGE/XL in the DBB are
changed to new "offending" entry. (It becomes the current
entry.) Note that this error check does not detect all
structural changes. DBGET (mode 5 or 6) makes check only
when preceding call on data set was successful DBFIND or
DBGET.
ACTION Begin reading chain again from first or last entry.