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API ReferenceC++ APIQueryResult

QueryResult

Full name: neug::QueryResult

Container for Cypher query execution results.

QueryResult provides convenient access to query results through both iterator-style (hasNext/next) and random access (operator[]) patterns. Results are returned as RecordLine objects containing Entry pointers.

Usage Example:

auto result = conn->Query("MATCH (n:Person) RETURN n.name, n.age LIMIT 100");
if (result.has_value()) {
  QueryResult& qr = result.value();
  // Method 1: Range-based for loop
  for (auto& record : qr) {
    std::cout << record.ToString() << std::endl;
  }
  // Method 2: Random access by index
  for (size_t i = 0; i < qr.length(); ++i) {
    RecordLine record = qr[i];
  }
  // Get result schema
  std::cout << "Schema: " << qr.get_result_schema() << std::endl;
}

Memory Model:

  • QueryResult owns the underlying protobuf data
  • RecordLine contains pointers to internal data (no copying)
  • Do not access records after QueryResult is destroyed

Constructors & Destructors

QueryResult()=default

Default constructor creating empty result.

  • Since: v0.1.0

QueryResult(results::CollectiveResults &&res)

Construct QueryResult from CollectiveResults.

  • Parameters:

    • res: CollectiveResults to be moved and stored

  • Since: v0.1.0

Public Methods

From(results::CollectiveResults &&result)

Create QueryResult from CollectiveResults (move semantics).

Factory method that creates a QueryResult by moving a CollectiveResults. QueryResult constructor with std::move.

  • Parameters:

    • result: CollectiveResults to be moved into the QueryResult

  • Returns: QueryResult containing the moved results

  • Since: v0.1.0

From(const std::string &result_str)

Create QueryResult by deserializing from a string.

Deserializes a CollectiveResults protobuf from string format.

  • Parameters:

    • result_str: Serialized CollectiveResults string

  • Throws:

    • std::runtime_error: if parsing fails

  • Returns: QueryResult containing the deserialized results

  • Since: v0.1.0

hasNext() const

Check if there are more records to iterate.

  • Returns: true if cur_index_ < result_.results_size(), false otherwise

  • Since: v0.1.0

next()

Get the next result record and advance iterator.

Returns a RecordLine containing pointers to Entry objects from the current record. Advances cur_index_ after retrieving the record.

  • Notes:

    • Returns pointers to internal data - no memory allocation or copying
    • Returns empty RecordLine if no more records (logs error)
    • Caller should check hasNext() before calling this method

  • Returns: RecordLine containing const Entry* pointers to record columns

  • Since: v0.1.0

operator[](int index) const

Get a record by index (random access).

  • Parameters:

    • index: Zero-based index of the record to retrieve

  • Notes:

    • Does not affect iterator state (cur_index_)
    • Returns pointers to internal data - no copying

  • Returns: RecordLine containing const Entry* pointers to record columns

  • Since: v0.1.0

length() const

Get total number of records in the result set.

  • Returns: Total number of result records

  • Since: v0.1.0

get_result_schema() const

Get the result schema as a string.

  • Returns: const std::string& Reference to the schema string from CollectiveResults

  • Since: v0.1.0

RecordLine

Full name: neug::RecordLine

A single row/record from query results.

RecordLine represents one row of query output, containing multiple column values (entries). Each entry corresponds to a RETURN clause expression in the Cypher query.

Usage Example:

auto result = conn->Query("MATCH (n:Person) RETURN n.name, n.age", "read");
for (auto& record : result.value()) {
  // Access entries by index
  const auto& entries = record.entries();
  // entries[0] = name, entries[1] = age
  std::cout << record.ToString() << std::endl;
}

Constructors & Destructors

RecordLine(std::vector< const results::Entry * > entries)

Construct RecordLine from entry pointers.

  • Parameters:
    • entries: Vector of pointers to result entries

Public Methods

ToString() const

Convert record to string representation.

  • Returns: String representation of all entries

entries() const

Get all entries (column values) in this record.

  • Returns: Vector of const pointers to Entry objects
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