FairCom ISAM for C

PreviousInVRange

Read the previous record in a range

Short Name

PRVVRNG()

Type

ISAM function

Declaration

COUNT PreviousInVRange(COUNT keyval, pVOID recptr, pVRLEN plen)

Description

Read the previous data record in a range established by a call to AllocateRange(). If successful, the record becomes the current ISAM record for the associated data file. A successful PreviousInVRange() defines a current key value set, and subsequent calls to NextInVRange() or PreviousInVRange() will read the other records in the range.

plen acts as both an input and output parameter:

• On input, plen contains the length of the output buffer.
• On output, the contents of plen is the actual data-record length. If the length of the output buffer is less than the actual record length, a partial read is performed. If an error occurs, plen is unspecified.

Return

Value	Symbolic Constant	Explanation
0	NO_ERROR	Successful operation.
101	INOT_ERR	Could not satisfy and ISAM search request for index isam_fil. This error frequently indicates "End of File" reached, or "Record not Found." The following items are the probable causes of the INOT_ERR (101). Passing GetRecord() a duplicate allowed index number (keyno). GetRecord() does not support duplicate allowed indices. Improper target padding. Review “Key Segment Modes” in the c-tree Plus Programmer’s Guide. Not calling TransformKey() on target. Refer to “TransformKey” in the Function Reference Guide Passing ctDeleteSequence() a sequence name that does not exist Improper segment mode. Review “Key Segment Modes” in the c-tree Plus Programmer’s Guide. ctFILBLK() is called and the file is already blocked.

See c-tree Error Codes for a complete listing of valid c-tree error values.

See also

AllocateRange(), EstimateRange(), FirstInRange(), FirstInVRange(), FreeRange(), LastInRange(), LastInVRange(), NextInRange(), NextInVRange(), PreviousInRange()