FairCom DB API API for C++ - Developers Guide

Find Modes

Use the following find modes with the record find methods:

FairCom DB API Find mode	FairCom DB API .NET Find Mode	Explanation
CTFIND_EQ	EQ	Find a record equal to the target
CTFIND_LT	LT	Find a record less than target
CTFIND_LE	LE	Find a record less or equal than target
CTFIND_GT	GT	Find a record greater than target
CTFIND_GE	GE	Find a record greater or equal than target

Note: The Find Mode CTFIND_EQ requires that the target contains values for all segments that compose the index and the index cannot allow duplicates.

Note: FairCom DB API .NET defines this mode with the FIND_MODE enum.

Building a target key

A target key can be built using most of the steps used to find a record using CTRecord::FindTarget() method. To build a target key you must:

1. Clear a record buffer
2. Set the default index with the appropriate value
3. Populate the fields that makeup the index segment
4. Call CTRecord::BuildTargetKey() with the appropriate find mode and the buffer to receive the target key

// build a target key

CTRecord ARecord(ATable);

TEXT key[256];

VRLEN keylen = sizeof(key);

// clear the record buffer

ARecord.Clear();

// set the default index to index 0

ARecord.SetDefaultIndex(0);

// populate the 'product' field

ARecord.SetFieldAsString("product", "DISKETTE");

// build the target key

try

{

ARecord.BuildTargetKey(CTFIND_EQ, key, &keylen);

}

catch (CTException &err)

{

printf("Build target key failed with error %d\n", err.GetErrorCode());

}

Finding records by target key

A record can also be found by passing a target key already built by calling CTRecord::FindTarget() method. CTRecord::FindTarget() takes as its parameters a pointer to a target key and the find mode.

// find record with a target key

CTRecord ARecord(ATable);

TEXT key[256];

VRLEN keylen = sizeof(key);

// clear the record buffer

ARecord.Clear();

// set the default index to index 0

ARecord.SetDefaultIndex(0);

// populate the 'product' field

ARecord.SetFieldAsString("product", "DISKETTE");

// build the target key

ARecord.BuildTargetKey(CTFIND_EQ, key, &keylen);

try

{

if (ARecord.FindTarget(key, CTFIND_EQ))

printf("Record found\n");

else

printf("Record not found\n");

}

catch (CTException &err)

{

printf("Find target failed with error %d\n", err.GetErrorCode());

}

Finding records by ROWID

A record can be quickly located if the ROWID for that record is known by calling CTRecord::FindRowid(). CTRecord::FindRowid() take as its parameters the ROWID value and the find mode.

// find record with rowid of 1000

CTRecord ARecord(ATable);

try

{
if (ARecord.FindRowid(1000, CTFIND_EQ))

printf("Record found\n");

else

printf("No record found\n");

}

catch (CTException &err)

{

printf("Find Rowid failed with error %d\n", err.GetErrorCode());

}