7.2 Example with Bulk and Vector Classes

The following example illustrates the use of RWDBBulkInserter, RWDBBulkReader, and the related vector classes RWDBVector, RWDBDateVector, and RWDBBinaryVector, to insert, read, and print out the values in the purchase table.

// Example Program 6 - Bulk reads and writes
void insertPurchaseTable(const RWDBDatabase& db) {
  RWDBTable tab = db.table("purchase");
  RWDBBulkInserter ins = tab.bulkInserter(db.connection());

  int vectorLength = 10;
  RWDBVector<int> videoID(vectorLength);
  RWDBVector<int> supplierID(vectorLength);
  RWDBVector<int> purchaseOrderNumber(vectorLength);
  RWDBVector<double> pricePerUnit(vectorLength);
  RWDBVector<int> quantity(vectorLength);
  
  // Note that we need a database to produce a vendor-specific 
  // date vector.
  RWDBDateVector dateVector = db.dateVector(vectorLength);

  // Bind the arrays to the inserter before execution.
  ins << videoID << supplierID <<  purchaseOrderNumber 
      << pricePerUnit  << quantity << dateVector;
  
  // Initiate data:
  RWDBDateTime now;
  for (int i = 0; i < vectorLength; i++) {
    videoID[i] = supplierID[i] = purchaseOrderNumber[i] =
      pricePerUnit[i] = quantity[i] = i;
    dateVector[i] = now;
  }

  ins.execute();
  return;
}

void readPurchaseTable(const RWDBDatabase& db) {
  RWDBTable tab = db.table("purchase");
  RWDBBulkReader rdr = tab.bulkReader(db.connection());

  int vectorLength = 10;
  RWDBVector<int> videoID(vectorLength);
  RWDBVector<int> supplierID(vectorLength);
  RWDBVector<int> purchaseOrderNumber(vectorLength);
  RWDBVector<double> pricePerUnit(vectorLength);
  RWDBVector<int> quantity(vectorLength);

  // Note that we need a database to produce a vendor-specific 
  // date vector.
  RWDBDateVector dateVector = db.dateVector(vectorLength);

  // Bind the arrays to the reader before execution.
  rdr << videoID << supplierID <<  purchaseOrderNumber 
      << pricePerUnit << quantity << dateVector;

  // Fetch up to vectorLength rows at a time.
  int rowsRead= 0;
  while (rowsRead = rdr()) {
    for (int i = 0; i < rowsRead; i++) {
      cout << videoID[i] << supplierID[i] 
           << purchaseOrderNumber[i] 
           << pricePerUnit[i] << quantity[i] 
           << dateVector[i].asString() << endl;
    }
  }
}