dynamicindexedviewexample.cpp

The goal of this library is to make ODBC recordsets look just like an STL container. As a user, you

// example showing the use of an indexed view in the dynamic case

#include "DynamicIndexedViewExample.h"

// Dynamic IndexedDBView example
void DynamicIndexedViewExample()
{
 DynamicDBView<ParamObjExample> dynamic_view("DB_EXAMPLE",
	 "INT_VALUE, STRING_VALUE, DOUBLE_VALUE, EXAMPLE_LONG,  EXAMPLE_DATE",
	 "WHERE INT_VALUE BETWEEN (?) AND (?) OR "
	  "STRING_VALUE = (?) OR EXAMPLE_DATE <= (?) ORDER BY EXAMPLE_LONG",
	  BPAExampleObj());


 // make the functor needed for SetParams out of SetParamsExample() by calling
 // cb_ptr_fun(SetParamsExample)
 
 DynamicIndexedDBView< DynamicDBView<ParamObjExample> >  
	 indexed_view(dynamic_view, 
     "PrimaryIndex; STRING_VALUE;"
     "UNIQUE IndexLongDate; EXAMPLE_LONG, EXAMPLE_DATE",
	 BOUND, USE_ALL_FIELDS, 
	 cb_ptr_fun(SetParamsExample));

 // Find the item where the STRING_VALUE matches the string  "Foozle"
 DynamicIndexedDBView< DynamicDBView<ParamObjExample>  >::indexed_iterator idxview_it =  indexed_view.find(string("Foozle"));;


 // Update the item with the key of "Foozle", to read  "Fizzle" instead
 if (idxview_it != indexed_view.end()) {
  variant_row replacement;
  replacement = *idxview_it;
  replacement["STRING_VALUE"] = string("Fizzle");
  TIMESTAMP_STRUCT date = {2003, 3, 3, 0, 0, 0, 0};
  replacement["EXAMPLE_DATE"] = date;
  indexed_view.replace(idxview_it, replacement);
 }

 // Now find a second set of items using AlternateIndex
 // The STL convention for equal_range is to return a pair  consisting of: 
 // 1. an iterator referring to the beginning of the list of found  items
 // 2. an iterator pointing to the end of the list of found items. 
 // We will remove all items in this range.
 const TIMESTAMP_STRUCT date_criteria = {2000, 1, 1, 0, 0, 0, 0};
 long long_criteria = 33;
 DynamicIndexedDBView< DynamicDBView<ParamObjExample> >::indexed_pair 
 pr = indexed_view.equal_range_AK("IndexLongDate", long_criteria, date_criteria);

 idxview_it = pr.first;

 cout << "*** Size before erase calls: " <<  indexed_view.size() << " ***"
 << endl;

 // Remove all rows that matched the criteria in our  equal_range_AK lookup
 while (idxview_it != pr.second)
 {
  // as iterator is invalidated upon an erase(), use a temporary   iterator
  // to point to DataObj to erase
  // increment idxview_it before we erase so it will still be valid
  // when we erase the DataObj
  DynamicIndexedDBView< DynamicDBView<ParamObjExample> >::indexed_iterator deleteMe = idxview_it;

  ++idxview_it;

  indexed_view.erase(deleteMe);

 }

 cout << "*** Size after erase calls: " <<  indexed_view.size() << " ***"
 << endl;


 // Finally, insert a new item into the container
 pair<DynamicIndexedDBView< DynamicDBView<ParamObjExample>  >::iterator, bool> ins_pr;
 variant_row r(indexed_view.DataObj());
 r["INT_VALUE"] = 459;
 r["STRING_VALUE"] = string("Unique String  #1");
 r["DOUBLE_VALUE"] = 3.5;
 r["EXAMPLE_LONG"] = 1;
 r["EXAMPLE_DATE"] = date_criteria;
 ins_pr = indexed_view.insert(r);
 cout << "insertion succeded = " <<  (ins_pr.second == true ? "true": "false")  << endl;

}