const Status RelCatalog::removeInfo(const string & relation)
{
Status status;
RID rid;
HeapFileScan* hfs;
if (relation.empty()) return BADCATPARM;
hfs = new HeapFileScan(RELCATNAME,status);
if (status != OK) return status;
hfs->startScan(0,relation.length(),STRING,relation.c_str(),EQ);
if (status != OK) return status;
status=hfs->scanNext(rid);
if (status != OK) return status;
status = hfs->deleteRecord();
if (status != OK) return status;
hfs->endScan();
delete hfs;
return OK;
}
const Status AttrCatalog::getInfo(const string & relation,
const string & attrName,
AttrDesc &record)
{
Status status;
RID rid;
Record rec;
HeapFileScan* hfs;
hfs = new HeapFileScan(ATTRCATNAME,status);
if (status != OK) return status;
hfs->startScan(0,sizeof(record.relName),STRING,relation.c_str(),EQ);
if (status != OK) return status;
while ((status=hfs->scanNext(rid)) != FILEEOF)
{
if (status != OK) return status;
status=hfs->getRecord(rec);
if (status != OK) return status;
if (strncmp((char*)rec.data + sizeof(record.relName),attrName.c_str(),sizeof(record.attrName))==0)
{
memcpy(&record,rec.data,rec.length);
break;
}
}
hfs->endScan();
delete hfs;
return OK;
}
const Status AttrCatalog::removeInfo(const string & relation,
const string & attrName)
{
Status status;
Record rec;
RID rid;
AttrDesc record;
HeapFileScan* hfs;
if (relation.empty() || attrName.empty()) return BADCATPARM;
hfs = new HeapFileScan(ATTRCATNAME,status);
if (status != OK) return status;
hfs->startScan(0,sizeof(record.relName),STRING,relation.c_str(),EQ);
if (status != OK) return status;
while ((status=hfs->scanNext(rid)) != FILEEOF)
{
if (status != OK) return status;
status=hfs->getRecord(rec);
if (status != OK) return status;
if (strncmp((char*)rec.data + sizeof(record.relName),attrName.c_str(),sizeof(record.attrName))==0)
{
status = hfs->deleteRecord();
if (status != OK) return status;
break;
}
}
hfs->endScan();
delete hfs;
return OK;
}
const Status RelCatalog::getInfo(const string & relation, RelDesc &record)
{
if (relation.empty())
return BADCATPARM;
Status status;
Record rec;
RID rid;
HeapFileScan * scan;
scan = new HeapFileScan(RELCATNAME,status);
if (status != OK) return status;
scan->startScan(0,sizeof(record.relName),STRING,relation.c_str(),EQ);
if (status != OK) return status;
status=scan->scanNext(rid);
if (status == FILEEOF) return RELNOTFOUND;
if ((status != FILEEOF) && (status != OK)) return status;
status=scan->getRecord(rec);
if (status != OK) return status;
memcpy(&record,rec.data,rec.length);
scan->endScan();
delete scan;
scan = NULL;
return OK;
}
const Status AttrCatalog::getRelInfo(const string & relation,
int &attrCnt,
AttrDesc *&attrs)
{
Status status;
RID rid;
Record rec;
HeapFileScan* hfs;
RelDesc rel;
if (relation.empty()) return BADCATPARM;
status = relCat->getInfo(relation, rel);
//if (status == FILEEOF) return RELNOTFOUND;
//if ((status != FILEEOF) && (status != OK)) return status;
if (status != OK) return status;
hfs = new HeapFileScan(ATTRCATNAME,status);
hfs->startScan(0,sizeof(attrs->relName),STRING,relation.c_str(),EQ);
if (status != OK) return status;
attrCnt = 0;
attrs = new AttrDesc[10];
while ((status=hfs->scanNext(rid)) != FILEEOF)
{
if (status != OK) return status;
status=hfs->getRecord(rec);
if (status != OK) return status;
memcpy(&attrs[attrCnt],rec.data,rec.length);
attrCnt++;
}
hfs->endScan();
delete hfs;
return OK;
}