#include 
       
        #include 
        
          #include 
         
          #include 
          
           #include 
           
             #include 
            
              using namespace std; const char* kDatabaseName = "access.db"; int main() { string fruit("fruit"); string apple("apple"); string orange("orange"); DbEnv env(0); Db* pdb; try { env.set_error_stream(&cerr); env.open("/Users/wangyi/db", DB_CREATE | DB_INIT_MPOOL, 0); pdb = new Db(&env, 0); // If you want to support duplicated records and make duplicated // records sorted by data, you need to call: // pdb->set_flags(DB_DUPSORT); // Note that only Btree-typed database supports sorted duplicated // records // If the database does not exist, create it. If it exists, clear // its content after openning. pdb->open(NULL, "access.db", NULL, DB_BTREE, DB_CREATE | DB_TRUNCATE, 0); Dbt key(const_cast
             
              (fruit.data()), fruit.size()); Dbt value(const_cast
              
               (apple.data()), apple.size()+1); pdb->put(NULL, &key, &value, 0); Dbt value_orange(const_cast
               
                (orange.data()), orange.size()+1); pdb->put(NULL, &key, &value_orange, 0); // You need to set ulen and flags=DB_DBT_USERMEM to prevent Dbt // from allocate its own memory but use the memory provided by you. char buffer[1024]; Dbt data; data.set_data(buffer); data.set_ulen(1024); data.set_flags(DB_DBT_USERMEM); if (pdb->get(NULL, &key, &data, 0) == DB_NOTFOUND) { cerr << "Not found" << endl; } else { cout << "Found: " << buffer << endl; } if (pdb != NULL) { pdb->close(0); delete pdb; // You have to close and delete an exisiting handle, then create // a new one before you can use it to remove a database (file). pdb = new Db(NULL, 0); pdb->remove("/Users/wangyi/db/access.db", NULL, 0); delete pdb; } env.close(0); } catch (DbException& e) { cerr << "DbException: " << e.what() << endl; return -1; } catch (std::exception& e) { cerr << e.what() << endl; return -1; } return 0;}