RocksIterator.cpp

rocksdb::Slice key1 = "1";
rocksdb::Slice key2 = "2";
rocksdb::Slice key3 = "3";
std::string val1 = "one";
std::string val2 = "two";
std::string val3 = "three";

// populate the database with entries
db->Put(rocksdb::WriteOptions(), key1, val1);
db->Put(rocksdb::WriteOptions(), key2, val2);
db->Put(rocksdb::WriteOptions(), key3, val3);

// create new iterator
rocksdb::Iterator* it = db->NewIterator(rocksdb::ReadOptions());

// iterate all entries
for (it->SeekToFirst(); it->Valid(); it->Next()) {
    cout << it->key().ToString() << ": " << it->value().ToString() << endl;
}
assert(it->status().ok());  // check for any errors found during the scan

cout << "---" << endl; // separator

// iterate entries within range [start, end)
for (it->Seek(key2); it->Valid() && it->key().ToString() < key3.ToString();
    it->Next()) {
    cout << it->key().ToString() << ": " << it->value().ToString() << endl;
}

cout << "---" << endl; // separator

// iterate all in reverse order
for (it->SeekToLast(); it->Valid(); it->Prev()) {
    cout << it->key().ToString() << ": " << it->value().ToString() << endl;
}

// destroy iterator object
delete it;