resultset.cpp

絲路server源碼 Silk Road server source

    case SQL_FETCH_ABSOLUTE:
      if(rowNum==0) {
        location_=BEFORE_FIRST;
      } else {
        location_=AFTER_LAST;
      }
      break;

    case SQL_FETCH_NEXT:
    case SQL_FETCH_LAST:
      location_=AFTER_LAST;
      break;

    case SQL_FETCH_FIRST:
    case SQL_FETCH_PRIOR:
      location_=BEFORE_FIRST;
      break;

    default:
      //notreached
      assert(false);
    }
  } else {

    // for forward only cursors, we don't bother fetching the location
    // we just increment it for each fetch

    if(isfo) {
      if(location_<=0) {
        location_=1;
      } else {
        location_+=currentFetchSize_;
      }
    } else {
      SQLUINTEGER l=statement_->_getNumericOption
        (ODBC3_C(SQL_ATTR_ROW_NUMBER,SQL_ROW_NUMBER));

      if(l==0) {
        location_=UNKNOWN;
      } else {
        location_=(int)l;
      }
    }
  }
}

void ResultSet::_handleStreams(SQLRETURN r)
{
  if(r==SQL_NEED_DATA) {
    ODBCXX_CHAR_TYPE buf[PUTDATA_CHUNK_SIZE];

    while(r==SQL_NEED_DATA) {
      SQLPOINTER currentCol;
      r=SQLParamData(hstmt_,&currentCol);
      this->_checkStmtError(hstmt_,r,ODBCXX_STRING_CONST("SQLParamData failure"));
      if(r==SQL_NEED_DATA) {
        DataHandler* dh=rowset_->getColumn((int)currentCol);

        assert(dh->isStreamed_);

        int charsPut=0;

        ODBCXX_STREAM* s=dh->getStream();
        
        int b;
        while((b=readStream(s,buf,PUTDATA_CHUNK_SIZE))>0) {
          charsPut+=b;
          SQLRETURN rPD=SQLPutData(hstmt_,(SQLPOINTER)buf,b*sizeof(ODBCXX_CHAR_TYPE));
          this->_checkStmtError(hstmt_,rPD,ODBCXX_STRING_CONST("SQLPutData failure"));
        }
        
        if(charsPut==0) {
          // SQLPutData has not been called
          SQLRETURN rPD=SQLPutData(hstmt_,(SQLPOINTER)buf,0);
          this->_checkStmtError(hstmt_,rPD,ODBCXX_STRING_CONST("SQLPutData(0) failure"));
        }
      }
    }
  }
}




int ResultSet::getType()
{
  return statement_->getResultSetType();
}

int ResultSet::getConcurrency()
{
  return statement_->getResultSetConcurrency();
}

void ResultSet::setFetchSize(int fs)
{
  CHECK_INSERT_ROW;

  if(fs==0) {
    fs=SQL_ROWSET_SIZE_DEFAULT; //1
  }

  if(fs>0) {
    newFetchSize_=fs;
    if(fs!=currentFetchSize_) {
      //ok, we'll need to change it
      //if we are before/after the resultset, it's ok to proceed now
      if(!LOCATION_IS_VALID) {
        currentFetchSize_=fs;
        this->_applyFetchSize();
      }
    }
  } else {
    throw SQLException
      (ODBCXX_STRING_CONST("[libodbc++]: Invalid fetch size ")+intToString(fs));
  }
}


bool ResultSet::next()
{
  CHECK_INSERT_ROW;

  if(LOCATION_IS_VALID &&
     rowset_->getCurrentRow()+1 < rowsInRowset_) {
    //we just move inside the rowset
    rowset_->setCurrentRow(rowset_->getCurrentRow()+1);
    this->_applyPosition();
    return true;
  } else if(location_==AFTER_LAST) {
    //no more to come
    return false;
  }

  //we now know for sure we have to do a fetch
  this->_prepareForFetch();
  this->_doFetch(SQL_FETCH_NEXT,0);

  if(LOCATION_IS_VALID) {
    this->_applyPosition();
    return true;
  }

  return false;
}

bool ResultSet::previous()
{
  CHECK_INSERT_ROW;

  CHECK_SCROLLABLE_CURSOR;


  if(LOCATION_IS_VALID &&
     rowset_->getCurrentRow()>0) {

    //alright, just move inside the rowset
    rowset_->setCurrentRow(rowset_->getCurrentRow()-1);
    this->_applyPosition();
    return true;

  } else if(location_==BEFORE_FIRST) {

    //no rows there..
    return false;

  } else {

    //if, we have, say a rowset that covers rows 10-30, and
    //we request the previous, we get rows 1-20. Then
    //we'll have to adjust to position to the
    //right row

    int oldloc=location_;

    this->_prepareForFetch();
    this->_doFetch(SQL_FETCH_PRIOR,0);

    if(LOCATION_IS_VALID) {
      if(oldloc>0 &&
         oldloc-location_ < currentFetchSize_) {
        rowset_->setCurrentRow(oldloc-2); //1 for 1-based location, 1 for previous
      } else {
        //just the last row in the rowset
        rowset_->setCurrentRow(rowsInRowset_-1);
      }
      this->_applyPosition();
      return true;
    } else {
      return false;
    }
  }
}


bool ResultSet::first()
{
  CHECK_INSERT_ROW;
  CHECK_SCROLLABLE_CURSOR;

  // don't trust any positions, just fetch the first rowset
  this->_prepareForFetch();
  this->_doFetch(SQL_FETCH_FIRST,0);

  if(LOCATION_IS_VALID) {
    this->_applyPosition();
    return true;
  }

  return false;
}


bool ResultSet::last()
{
  CHECK_INSERT_ROW;
  CHECK_SCROLLABLE_CURSOR;

  this->_prepareForFetch();
  this->_doFetch(SQL_FETCH_LAST,0);

  if(LOCATION_IS_VALID) {
    rowset_->setCurrentRow(rowsInRowset_-1);
    this->_applyPosition();
    return true;
  } else {
    return false;
  }
}

bool ResultSet::relative(int rows)
{
  CHECK_INSERT_ROW;
  CHECK_SCROLLABLE_CURSOR;

  if(!LOCATION_IS_VALID) {
    throw SQLException
      (ODBCXX_STRING_CONST("[libodbc++]: ResultSet::relative(): no current row"));
  }

  if(rows==0) {
    return true;
  }

  if(rows>0 && rowset_->getCurrentRow() < rowsInRowset_-rows) {
    rowset_->setCurrentRow(rowset_->getCurrentRow()+rows);
  } else if(rows<0 && rowset_->getCurrentRow() >= -rows) {
    rowset_->setCurrentRow(rowset_->getCurrentRow()+rows);
  } else {

    //since SQL_FETCH_RELATIVE is relative to the start of the rowset
    //we'll need to adjust
    rows-=rowset_->getCurrentRow();

    this->_prepareForFetch();
    this->_doFetch(SQL_FETCH_RELATIVE,rows);
  }

  if(LOCATION_IS_VALID) {
    this->_applyPosition();
    return true;
  } else {
    return false;
  }
}


bool ResultSet::absolute(int row)
{
  CHECK_INSERT_ROW;
  CHECK_SCROLLABLE_CURSOR;

  this->_prepareForFetch();

  this->_doFetch(SQL_FETCH_ABSOLUTE,row);

  if(LOCATION_IS_VALID) {
    this->_applyPosition();
    return true;
  }

  return false;
}

void ResultSet::beforeFirst()
{
  CHECK_INSERT_ROW;
  CHECK_SCROLLABLE_CURSOR;

  if(location_!=BEFORE_FIRST) {
    this->absolute(0);
  }
}

void ResultSet::afterLast()
{
  CHECK_INSERT_ROW;
  CHECK_SCROLLABLE_CURSOR;

  if(location_!=AFTER_LAST) {
    this->_prepareForFetch();

    this->_doFetch(SQL_FETCH_LAST,0); //now on last rowset
    this->_doFetch(SQL_FETCH_NEXT,0); //now after last rowset
  }
}



void ResultSet::moveToInsertRow()
{
  CHECK_SCROLLABLE_CURSOR;

  if(location_!=INSERT_ROW) {
    rowBeforeInsert_=rowset_->getCurrentRow();
    locBeforeInsert_=location_;

    rowset_->setCurrentRow(currentFetchSize_);


    location_=INSERT_ROW;
  }
}

void ResultSet::moveToCurrentRow()
{
  CHECK_SCROLLABLE_CURSOR;

  if(location_==INSERT_ROW) {

    if(bindPos_>0) {
      assert(this->_getDriverInfo()->getMajorVersion()>2);
      // this occurs after we have inserted rows
      // with an ODBC3 driver
      // restore our fetch size and
      // rebind with the real positions
      statement_->_setNumericOption
        (ODBC3_C(SQL_ATTR_ROW_ARRAY_SIZE,SQL_ROWSET_SIZE),
         currentFetchSize_);

      rowset_->setCurrentRow(0);
      this->_bindCols();

      // this mirrors rowset_->getCurrentRow()
      assert(bindPos_==0);

      if(locBeforeInsert_>0) {
        // we know our remembered position
        this->_doFetch(SQL_FETCH_ABSOLUTE, locBeforeInsert_);
      } else {

        switch(locBeforeInsert_) {
        case AFTER_LAST:
          this->_doFetch(SQL_FETCH_ABSOLUTE,-1);
          this->_doFetch(SQL_FETCH_NEXT,0);
          break;

        case BEFORE_FIRST:
        case UNKNOWN: // inconsistent
        default:
          this->_doFetch(SQL_FETCH_ABSOLUTE,0);
        }
      }

    } else {

      // we are in the right rowset already
      location_=locBeforeInsert_;

    }

    if(LOCATION_IS_VALID) {
      rowset_->setCurrentRow(rowBeforeInsert_);
      this->_applyPosition();
    } else {
      rowset_->setCurrentRow(0);
    }
  }
}

void ResultSet::insertRow()
{
  CHECK_SCROLLABLE_CURSOR;

  if(location_==INSERT_ROW) {

    // first, decide whether we use SQLBulkOperations
    // or SQLSetPos
#if ODBCVER >= 0x0300
    if(this->_getDriverInfo()->getMajorVersion()==3) {

      if(bindPos_==0) {
        // this is the first time we call insertRow()
        // while on the insert row
        statement_->_setNumericOption
          (ODBC3_C(SQL_ATTR_ROW_ARRAY_SIZE,SQL_ROWSET_SIZE),1);
        // this would bind only the last row of our rowset
        this->_bindCols();

        assert(bindPos_>0);
      }

      this->_bindStreamedCols();

      SQLRETURN r=SQLBulkOperations(hstmt_,SQL_ADD);

      try {
        this->_checkStmtError(hstmt_,r,ODBCXX_STRING_CONST("SQLBulkOperations failed"));
      } catch(...) {
        this->_unbindStreamedCols();
        throw;
      }

      this->_handleStreams(r);

      this->_unbindStreamedCols();

      rowset_->afterUpdate();
      return;
    }
#endif

    // we are using SQLSetPos(SQL_ADD) to insert a row
    SQLRETURN r;
    this->_bindStreamedCols();

    try {
      r=this->_applyPosition(SQL_ADD);
    } catch(...) {
      this->_unbindStreamedCols();
      throw;
    }

    this->_handleStreams(r);
    this->_unbindStreamedCols();
    rowset_->afterUpdate();

  } else {
    throw SQLException
      (ODBCXX_STRING_CONST("[libodbc++]: Not on insert row"));
  }
}

void ResultSet::updateRow()
{
  CHECK_SCROLLABLE_CURSOR;

  CHECK_INSERT_ROW;

  if(!LOCATION_IS_VALID) {
    throw SQLException
      (ODBCXX_STRING_CONST("[libodbc++]: No current row"));
  }

  this->_bindStreamedCols();
  // With ODBC3, the operation below will change our
  // rowsInRowset_, so we save it
  SQLRETURN r;
  {
#if ODBCVER >= 0x0300
    ValueSaver<SQLUINTEGER> _rows(rowsInRowset_);
#endif

    r=this->_applyPosition(SQL_UPDATE);
  }

  this->_handleStreams(r);


  this->_unbindStreamedCols();

  rowset_->afterUpdate();
}

void ResultSet::refreshRow()
{
  CHECK_SCROLLABLE_CURSOR;