Example #1
0
const Status RelCatalog::help(const string & relation)
{
  Status s;
  RelDesc rd;
  AttrDesc *attrs;
  int attrCnt;
  RID rid;
  Record rec;
  if (relation.empty()) return UT_Print(RELCATNAME);

  /** my code starts here **/
  // check if relation exists
  s = relCat->getInfo(relation, rd);
  if(s != OK){
    return RELNOTFOUND;
  }
  HeapFileScan* hfs = new HeapFileScan(RELCATNAME, s);
  CHKSTAT(s);
  s = hfs->startScan(0, MAXNAME, STRING, relation.c_str(), EQ);
  s = hfs->scanNext(rid);
  CHKSTAT(s);
  s = hfs->getRecord(rec);
  CHKSTAT(s);
  memcpy((void*)&rd, rec.data, rec.length);
  printf("Relation name: %s, (%d Attributes)\n", rd.relName, rd.attrCnt);
  printf("==========================================\n");
  printf("Attribute Name\tOffset\tType\tLength\n");
  delete hfs;
  hfs = new HeapFileScan(ATTRCATNAME, s);
  CHKSTAT(s);
  s = hfs->startScan(0, MAXNAME, STRING, relation.c_str(), EQ);
  CHKSTAT(s);
  attrs = new AttrDesc[rd.attrCnt];
  for(int i = 0; i < rd.attrCnt; i++){
    s = hfs->scanNext(rid);
    CHKSTAT(s);
    s = hfs->getRecord(rec);
    CHKSTAT(s);
    memcpy(attrs+i, rec.data, rec.length);
  }
  for(int i = 0; i < rd.attrCnt; i++){
    printf("%s\t\t%d\t%d\t%d\n", attrs[i].attrName, attrs[i].attrOffset, attrs[i].attrType, attrs[i].attrLen);
  }
  delete[] attrs;
  attrs = NULL;
  delete hfs;
  hfs = NULL;
  return OK;
}
Example #2
0
const Status RelCatalog::getInfo(const string & relation, RelDesc &record)
{
	
	Status status = OK;
	Record rec;
	RID rid;
	//heapfile scan
	
	if (relation.empty()) return BADCATPARM;
	
	while (status == OK) 
	{
		// Open a scan on the relcat relation by invoking the startScan() method on itself. 
		HeapFileScan* hfs = new HeapFileScan(RELCATNAME, status);
		status = hfs->startScan(0, relation.length() + 1, STRING, relation.c_str(), EQ);
		// You want to look for the tuple whose first attribute matches the string relName. 
		// Then call scanNext() and getRecord() to get the desired tuple.
		status = hfs->scanNext(rid);
		
		status = hfs->getRecord(rec);
		// Finally, you need to memcpy() the tuple out of the buffer pool into the return parameter record.
		memcpy((void*)&record, rec.data, rec.length);
		return status;
	}
	if (status == FILEEOF)
	{
		return RELNOTFOUND;
	}
	return status;
}
Example #3
0
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;
}
Example #4
0
//
// Remove the tuple corresponding to relName from relcat. It performs the following steps:
//
//      start a filter scan on relcat to locate the rid of the desired tuple     
//      call deleteRecord() to remove the tuple
//
// Returns:
//      OK on success
//      error code otherwise
//
const Status RelCatalog::removeInfo(const string & relation)
{
  Status status;
  RID rid;
  HeapFileScan*  hfs;

  if (relation.empty()) return BADCATPARM;

  //create a new file scan
  hfs=new HeapFileScan(RELCATNAME, status);
  if (status!=OK)
    return status;

  const char * relation_name_ptr = relation.c_str();
  // open startScan, use the predicate to find matching record
  status=hfs->startScan(0, MAXNAME, STRING, relation_name_ptr, EQ);
  if (status!=OK)
    return status;

  Record rec;
  // scan through relation catalog
  // assume there is no duplicate
  while ((status = hfs->scanNext(rid)) != FILEEOF){
    // get record
    status = hfs->getRecord(rec);
    if (status!=OK)
      return status;

    //delete current record
    hfs->deleteRecord();
    delete hfs;
    return OK;
  }
  return RELNOTFOUND;
}
Example #5
0
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;
}
Example #6
0
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;
}
Example #7
0
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;
}
Example #8
0
const Status RelCatalog::removeInfo(const string & relation)
{
	Status status = OK;
	RID rid;
	HeapFileScan* hfs;
	
	if (relation.empty()) return BADCATPARM;
	
	while (status == OK) 
	{
		hfs = new HeapFileScan(RELCATNAME, status);
		// you have to start a filter scan on relcat to locate the rid of the desired tuple.
		status = hfs->startScan(0, relation.length() + 1, STRING, relation.c_str(), EQ);
		
		status = hfs->scanNext(rid);
		// delete the record
		status = hfs->deleteRecord();   
		break;
	}
	if (status == NORECORDS)
	{
		return OK;
	}
	else if (status == FILEEOF)
	{
		return RELNOTFOUND;
	}
	else {
		return status;
	}
	
}
Example #9
0
const Status QU_Delete(const string & relation, 
		       const string & attrName, 
		       const Operator op,
		       const Datatype type, 
		       const char *attrValue)
{
  Status status;
  HeapFileScan *hfs;
  AttrDesc record;
  RID rid;
  int tempInt;
  float tempFloat;

  hfs = new HeapFileScan(relation, status);

  //Get the AttrDesc from the attrCat table
  if (attrValue != NULL){
    status = attrCat->getInfo(relation, attrName, record);
    if (status != OK) return status;
  }
  

  //check type and cast accordingly
  if(type == INTEGER){
    tempInt = atoi(attrValue);
    attrValue = (char *) &tempInt;
  } else if(type == FLOAT){
    tempFloat = atof(attrValue);
    attrValue = (char *) &tempFloat;
  }

  //Start HFS on the relation table
  status = hfs->startScan(record.attrOffset, record.attrLen, type, attrValue, op);
  if(status != OK) return status;

  while((status = hfs->scanNext(rid)) != FILEEOF){

    if(status != OK) return status;
    //Delete record if found in relation table
    status = hfs->deleteRecord();
    if(status != OK) return status;
  }
  
  //If end of file then return attribute not found
  if (status == FILEEOF){
    status = OK;
  }

  delete hfs;
  return status;


}
Example #10
0
const Status AttrCatalog::getRelInfo(const string & relation, 
				     int &attrCnt,
				     AttrDesc *&attrs)
{
	Status status = OK;
	RID rid;
	Record rec;
	HeapFileScan* hfs;
	hfs = new HeapFileScan(ATTRCATNAME, status);

	if (relation.empty()) return BADCATPARM;

// 	status = relCat->getInfo(relation,description);
// 	if (status != OK) {
// 		return status;
// 	}
// 	attrCnt = description.attrCnt;
// 	attrs = new AttrDesc[attrCnt];
	while (status == OK)
	{
		status = hfs->startScan(0, relation.length() + 1, STRING, relation.c_str(), EQ);
		attrCnt = 0;
		
		while (hfs->scanNext(rid) != FILEEOF)
		{
			status = hfs->getRecord(rec);
			attrCnt = attrCnt + 1;
			// First run through, create attrs.
			if (attrCnt == 1)
			{
				attrs = (AttrDesc*)(malloc(sizeof(AttrDesc)));
			}
			// Expand attrs
			else {
				attrs = (AttrDesc*)(realloc(attrs, attrCnt * sizeof(AttrDesc)));
			}
			memcpy(&attrs[attrCnt - 1], rec.data, rec.length);
		}
		break;
	}
	if (status == FILEEOF) {
		status = OK;
	}
// 	else if (attrCnt == 0)
// 	{
// 		return RELNOTFOUND;
// 	}
	else
	{
		return status;
	}

}
Example #11
0
//
// Gets descriptors for all attributes of the relation via attr, an array of AttrDesc structures
// and the count of the number of attributes in attrCnt
//
// Returns:
//      OK on success
//      error code otherwise
//
const Status AttrCatalog::getRelInfo(const string & relation, 
				     int &attrCnt,
				     AttrDesc *&attrs)
{
  Status status;
  RID rid;
  Record rec;
  HeapFileScan*  hfs;

  if (relation.empty()) return BADCATPARM;
  
  RelDesc relRec;
  
  if((status = relCat->getInfo(relation,relRec)) != OK)
      return status;
  
  attrs = new AttrDesc[relRec.attrCnt];
  int i = 0;
  hfs = new HeapFileScan(ATTRCATNAME,status);
  if(status != OK)
      return status;
  
  const char* rel_name_ptr = relation.c_str();
  
  status = hfs->startScan(0,MAXNAME,STRING, rel_name_ptr,EQ);
  if(status != OK){
      delete hfs;
      return status;
  }
  
  while((status = hfs->scanNext(rid)) != FILEEOF){
      status = hfs->getRecord(rec);
      if(status != OK){
	  delete hfs;
	  return status;
      }
      memcpy(&attrs[i],rec.data,sizeof(AttrDesc));
      i++;
  }
  delete hfs;
  
  if(i != relRec.attrCnt)
      return ATTRNOTFOUND;
  else{
    attrCnt = relRec.attrCnt;
      return OK;
  }
}
Example #12
0
const Status QU_Delete(const string & relation, 
		const string & attrName,
		const Operator op,
		const Datatype type,
		const char *attrValue)
{
	Status status;
	Status ScanStatus = OK;
	RID rid;
	AttrDesc *ad;
	int attrCnt;

	HeapFileScan *hfs = new HeapFileScan(relation,status);
	if(status != OK) {delete(hfs); return status;}
	status = attrCat->getRelInfo(relation, attrCnt, ad);
	if(status != OK) {delete(hfs); return status;}

	// Find out the attribute's size
	int attrSize;
	int attrOffset;
	for(int i = 0; i < attrCnt; i++)
		if(strcmp(ad[i].attrName,attrName.c_str()) == 0) {
			attrSize = ad[i].attrLen;
			attrOffset = ad[i].attrOffset;
		}
	// Start a scan (* DO WE NEED TO CAST ATTRVALUE??)
	status = hfs->startScan(attrOffset,attrSize,type,attrValue,op);
		if(status != OK) {delete(hfs); return status;}

	// Find and delete all matching records
	ScanStatus = hfs->scanNext(rid);
	while(ScanStatus != FILEEOF){

		status = hfs->deleteRecord();
		if(status != OK) {delete(hfs); return status;}
		ScanStatus = hfs->scanNext(rid);
		if(ScanStatus == FILEEOF)
		{delete(hfs);
		return OK;
		}
	}

	// Done
	delete(hfs);
	return ScanStatus;
}
Example #13
0
const Status AttrCatalog::removeInfo(const string & relation, 
			       const string & attrName)
{
	Status status = OK;
	Record rec;
	RID rid;
	AttrDesc record;
	HeapFileScan* hfs;
	
	if (relation.empty() || attrName.empty()) return BADCATPARM;

	while (status == OK) 
	{
		hfs = new HeapFileScan(ATTRCATNAME, status);
		// you have to start a filter scan on relcat to locate the rid of the desired tuple.
		status = hfs->startScan(0, relation.length() + 1, STRING, relation.c_str(), EQ);
		
		while (hfs->scanNext(rid) != FILEEOF)
		{
			status = hfs->getRecord(rec);
			memcpy(&record, rec.data, rec.length);
			if (strcmp(record.attrName, attrName.c_str()) == 0)
			{
				// Then you can call deleteRecord() to remove it
				status = hfs->deleteRecord();
				// break instead?
				return status;
			}
			  
		}
		break;
	}
	if (status == FILEEOF)
	{
		return status;
	}
	else if (status == NORECORDS)
	{
		return OK;
	}
	else {
		return status;
	}
}
Example #14
0
//
// Removes the tuple from attrcat that corresponds to attribute attrName of relation.
//
// Returns:
//      OK on success
//      error code otherwise
//
const Status AttrCatalog::removeInfo(const string & relation, 
			       const string & attrName)
{
  Status status;
  Record rec;
  RID rid;
  HeapFileScan*  hfs;

  if (relation.empty() || attrName.empty()) return BADCATPARM;
  
  hfs = new HeapFileScan(ATTRCATNAME,status);
  if(status != OK)
      return status;
  
  const char* rel_name_ptr = relation.c_str();
  const char* attr_name_ptr = attrName.c_str();
  
  status = hfs->startScan(0,MAXNAME,STRING,rel_name_ptr,EQ);
  if(status != OK){
      delete hfs;
      return status;
  }

  //first search all the attribute correspond to the relation
  while((status = hfs->scanNext(rid)) != FILEEOF){
      status = hfs->getRecord(rec);
      if(status != OK){
	  delete hfs;
	  return status;
      }
      //find the attribute
      if(memcmp(attr_name_ptr,((AttrDesc *)rec.data)->attrName,attrName.length() ) == 0){
	  //attribute found and detele
	  hfs->deleteRecord();
	  delete hfs;
	  //decrease the relation attrCnt
          return OK;
      }
  }
  delete hfs;
  return ATTRNOTFOUND;
}
Example #15
0
//
// Gets the attribute descriptor record for attribute attrName in relation relName. It performs the following steps:
//      
//      uses a scan over the underlying heapfile to get all tuples for relation
//      check each tuple to find whether it corresponds to attrName.
//
// Returns:
//      OK on success
//      error code otherwise
//
const Status AttrCatalog::getInfo(const string & relation, 
				  const string & attrName,
				  AttrDesc & record)
{
  Status status;
  RID rid;
  Record rec;
  HeapFileScan*  hfs;

  if (relation.empty() || attrName.empty()) return BADCATPARM;

  hfs = new HeapFileScan(ATTRCATNAME, status);
  if(status != OK)
      return status;

  const char* rel_name_ptr = relation.c_str();
  const char* attr_name_ptr = attrName.c_str();
  
  status = hfs->startScan(0,MAXNAME,STRING,rel_name_ptr,EQ);
  if(status != OK){
      delete hfs;
      return status;
  }  
  while( (status = hfs->scanNext(rid)) != FILEEOF){

    status = hfs->getRecord(rec);


    if(status != OK){
      delete hfs;
      return status;
    }
    if(memcmp(attr_name_ptr,((AttrDesc *)rec.data)->attrName,attrName.length()) == 0){
      memcpy(&record,rec.data,sizeof(AttrDesc));
      delete hfs;
      return OK;
    }
  }
  delete hfs;
  return ATTRNOTFOUND;
}
Example #16
0
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;

}
Example #17
0
// Returns the attribute descriptor record for attribute attrName in relation relName. 
const Status AttrCatalog::getInfo(const string & relation, 
				  const string & attrName,
				  AttrDesc &record)
{

	Status status = OK;
	RID rid;
	Record rec;
	HeapFileScan*  hfs;
	hfs = new HeapFileScan(ATTRCATNAME, status);

	if (relation.empty() || attrName.empty()) return BADCATPARM;
	// Uses a scan over the underlying heapfile to get all tuples for relation 
	// and check each tuple to find whether it corresponds to attrName. 
	while (status == OK)
	{
		status = hfs->startScan(0, relation.length() + 1, STRING, relation.c_str(), EQ);
		while (hfs->scanNext(rid) != FILEEOF)
		{
			status = hfs->getRecord(rec);
			memcpy(&record, rec.data, rec.length);
			if (strcmp(record.attrName, attrName.c_str()) == 0)
			{
				// Break here?
				return status;
			}
		}
		break;
	}
	if (status == FILEEOF)
	{
		return ATTRNOTFOUND;
	}
	return status;

}
Example #18
0
const Status QU_Update(const string & relation,
                       const int attrCnt,
                       const attrInfo attrList[],
                       const string & attrName,
                       const Operator op,
                       const Datatype type,
                       const char *attrValue)

{	
	
//typedef struct {
//  char relName[MAXNAME];                // relation name
//  char attrName[MAXNAME];               // attribute name
//  int attrOffset;                       // attribute offset
//  int attrType;                         // attribute type
//  int attrLen;                          // attribute length
//} AttrDesc;
//	typedef struct {
//  char relName[MAXNAME];                // relation name
//  char attrName[MAXNAME];               // attribute name
//  int  attrType;                        // INTEGER, FLOAT, or STRING
//  int  attrLen;                         // length of attribute in bytes
//  void *attrValue;                      // ptr to binary value
//} attrInfo; 
	 Status status;
	 HeapFileScan  *hfs;  
	  InsertFileScan *ifs;
	 AttrDesc   rd,temp[attrCnt];
	 int   tempi,tempa;
	 float tempf,tempb;
	 RID rid,Rid;
	 Record  rec,recd;
    int i=0;
    if (relation.empty())
    	 return BADCATPARM;
    ifs=new  InsertFileScan(relation,status);
 	  if(status!=OK)
  		return status;
     hfs=new  HeapFileScan(relation,status);
     if(status!=OK)
	  	return status;
//    	 cout<< "------------attrCnt       "<< attrCnt<<endl;
//    	 cout<<" ------------- relation       "<< relation<<endl;  	 
//    	 for(int i=0;i<attrCnt;i++)
//    	 {
//    	 	cout<<i<<"           "<<" attrList->relName               "<< attrList[i].relName<<endl;
//    	 	cout<<i<<"           "<<" attrList->attrName              "<< attrList[i].attrName<<endl;
//    	 	cout<<i<<"            "<<"attrList->attrType                 "<< attrList[i].attrType<<endl;
//    	 	cout<<i<<"            "<<"attrList->attrLen               "<< attrList[i].attrLen<<endl;
//    	 	cout<<i<<"            "<<"attrList-attrValue              "<< attrList[i].attrValue<<endl;	 	
//    	}
//    	 cout<<"  ------------ attrName           "<< attrName<<endl;
//	if((status=QU_Insert(relation, attrCnt, attrList))!=OK)
//		return status;
//	if((status=QU_Delete(relation,  attrName, op, type,  attrValue))!=OK)
//		return status;
if((status=attrCat->getInfo(relation, attrName,rd))!=OK)
	return status;
   	 	cout<<"           "<<" rd.relName               "<< rd.relName<<endl;
    	cout<<"           "<<" rd.attrName              "<< rd.attrName<<endl;
   	 	cout<<"            "<<"rd.attrType                 "<< rd.attrType<<endl;
   	 	cout<<"            "<<"rd.attrLen                  " << rd.attrLen<<endl;
   	 	cout<<"            "<<"ard.attrOffset            "<< rd.attrOffset<<endl;	 
  switch(rd.attrType)
    {
    case INTEGER:
     tempi=atoi(attrValue);
	 if((status=hfs->startScan(rd. attrOffset,rd. attrLen, INTEGER, (char*)&tempi,op))!=OK)
	    return OK;
      break;
    case FLOAT:
      tempf=atof(attrValue);
      if(( status=hfs->startScan(rd. attrOffset ,rd. attrLen ,FLOAT,(char*)&tempf,op))!=OK)
      	 return status;
      break;
    default:
     if(( status=hfs->startScan(rd. attrOffset,rd. attrLen ,STRING,(char*)attrValue,op))!=OK)
     	return  status;
      break;
    }  
  
      while ((status=hfs->scanNext(rid)) != FILEEOF)
	  {   
	  	      i=i+1;
		   if((status=hfs->getRecord(rec))!=OK)
	      	return status;
		  char data[rec.length];	
		  memcpy(&data, rec.data,rec.length );	 
		 if((status=hfs-> deleteRecord())!=OK)
		 	return status;
		 	
		// cout<<"---------------"<<rec.length<<endl;
		for(int j=0;j<attrCnt;j++)
		{
			if((status=attrCat->getInfo(attrList[j].relName, attrList[j].attrName,temp[j]))!=OK)
				return status;
//			  switch(temp[j].attrType)
//			    {
//			    case INTEGER:
//			     tempa=atoi((char *)attrList[j].attrValue);
//   				 memcpy(&data[ temp[j].attrOffset], &tempa,temp[j]. attrLen );   覆盖数据 
//				    return OK;
//			      break;
//			    case FLOAT:
//			     tempb=atof((char *)attrList[j].attrValue);
//				 memcpy(&data[ temp[j].attrOffset], &tempb,temp[j]. attrLen );   覆盖数据 
//			      break;
//			    default:
//			  	  memcpy(&data[ temp[j].attrOffset],(char *)attrList[j].attrValue,temp[j]. attrLen );   覆盖数据  
//			      break;
  			// memcpy(&data[ temp[j].attrOffset],(char *)attrList[j].attrValue,temp[j]. attrLen );   //覆盖数据   
  			  }  
		// recd.data=data;
   //   recd.length=rec.length;
   //   cout<<"1111111111111111"<<endl;
	//  if((status=ifs->insertRecord(recd, Rid))!=OK)
	       //   return status;  
	}
		//
	 cout<<" 总共找到的个数  --------------         "<<i<<endl;
	 delete hfs;
	 delete ifs;
	return OK;
}
Example #19
0
/**
 * FUNCTION: ScanSelect
 *
 * PURPOSE:  Selects records from the specified relation.
 *
 * PARAMETERS:
 *		result 			(out)		Relation name where result is to be stored
 *		projCnt			(in)		Count of projections
 *		projNames_Descs	(in)		Attribute description array of projections
 *		filterAttr		(in)		Attribute description of the attribute to be matched
 *		op				(in)		Operator to be used for matching
 *		filterValue		(in)		Value to be used for matching
 *		reclen			(in)		Length of the filter value
 *	
 * RETURN VALUES:
 *		Status  	OK         		Selected records successfully found and returned
 *                  BADCATPARM      Relation name is empty
 *                  BADSCANPARM     Error in allocating page: All buffer frames are pinned
 *                  FILEEOF         Reached the end of file while scanning for the record
 *                  BUFFEREXCEEDED  All buffer frames are pinned
 *                  HASHTBLERROR    Hash table error occurred
 *                  PAGENOTPINNED   Pin count is already 0
 *                  HASHNOTFOUND    Page is not in the buffer pool hash table
 **/
const Status ScanSelect(const string & result, 
			const int projCnt, 
			const AttrDesc projNames_Descs[],
			const AttrDesc *filterAttr, 
			const Operator op, 
			const char *filterValue,
			const int reclen)
{
	cout << "Doing HeapFileScan Selection using ScanSelect()" << endl;
	Record rec;
	RID rid;
	Status status;
	
	HeapFileScan* hfs = new HeapFileScan(projNames_Descs[0].relName, status);
	if (status != OK)
	{
		delete hfs;
		return status;
	}

	if(filterAttr == NULL)
	{
		if ((status = hfs->startScan(0, 0, STRING,  NULL, EQ)) != OK)
		{
			delete hfs;
			return status;
		}
	}
	else
	{
		int intValue;
		float floatValue;
		switch(filterAttr->attrType)
		{
			case STRING:
				status = hfs->startScan(filterAttr->attrOffset, filterAttr->attrLen, (Datatype) filterAttr->attrType, filterValue, (Operator) op);
				break;
		
			case INTEGER:
		 		intValue = atoi(filterValue);
				status = hfs->startScan(filterAttr->attrOffset, filterAttr->attrLen, (Datatype) filterAttr->attrType, (char *)&intValue, (Operator) op);
				break;
		
			case FLOAT:
				floatValue = atof(filterValue);
				status = hfs->startScan(filterAttr->attrOffset, filterAttr->attrLen, (Datatype) filterAttr->attrType, (char *)&floatValue, (Operator) op);
				break;
		}
		
		if(status != OK)
		{
			delete hfs;
			return status;
		}
	}
	
	while ((status = hfs->scanNext(rid)) == OK)
	{
 		if (status == OK)
  		{
  			status = hfs->getRecord(rec);
			if (status != OK)
				break;
          	
    		attrInfo attrList[projCnt];
			int value = 0; char buffer[33];
			float fValue;
    		for(int i = 0; i < projCnt; i++)
			{
				AttrDesc attrDesc = projNames_Descs[i];
  	  			
  	  			strcpy(attrList[i].relName, attrDesc.relName);
  	  			strcpy(attrList[i].attrName, attrDesc.attrName);
  	  			attrList[i].attrType = attrDesc.attrType;
  	  			attrList[i].attrLen = attrDesc.attrLen;
  	  			
  	  			attrList[i].attrValue = (void *) malloc(attrDesc.attrLen);
  	  			
				switch(attrList[i].attrType)
				{
					case STRING: 
						 memcpy((char *)attrList[i].attrValue, (char *)(rec.data + attrDesc.attrOffset), attrDesc.attrLen);
						 break;
						 
					case INTEGER: 
						memcpy(&value, (int *)(rec.data + attrDesc.attrOffset), attrDesc.attrLen);
						sprintf((char *)attrList[i].attrValue, "%d", value);
						break;
						 
					case FLOAT: 
 						memcpy(&fValue, (float *)(rec.data + attrDesc.attrOffset), attrDesc.attrLen);
 						sprintf((char *)attrList[i].attrValue, "%f", fValue);
						break;
				}
  			}
  		
  			status = QU_Insert(result, projCnt, attrList);
  			if(status != OK)
			{
				delete hfs;
				return status;
			}
  		}
	}
		
	return OK;
}