QueryResult

Full name: neug::QueryResult

Lightweight wrapper around protobuf QueryResponse.

QueryResult stores a full query response and exposes utility methods for:

• constructing from serialized protobuf bytes (From()),
• obtaining row count (length()),
• accessing response schema (result_schema()),
• serializing/deserializing (Serialize() / From()),
• debugging output (ToString()),
• cursor-based row traversal via hasNext() / next(),
• typed cell access via GetInt32(), GetString(), etc.

Cursor Traversal

hasNext() const

Check whether there are more rows to consume.

next()

Advance the cursor to the next row. Throws if no more rows are available.

Reset()

Reset the internal cursor back to the first row.

CurrentRowIndex() const

Return the current cursor position (0-based row index).

Typed Value Accessors

All getters read from the current cursor row. Each method has two overloads: by column index or by column name.

IsNull(size_t column_index) / IsNull(const std::string& column_name)

Check whether the cell at current row is NULL.

GetInt32(...) — accepts int32, bool

GetUInt32(...) — accepts uint32, bool

GetInt64(...) — accepts int64, int32, uint32, bool, date, timestamp (date/timestamp return the raw int64 epoch value)

GetUInt64(...) — accepts uint64, uint32, bool

GetFloat(...) — accepts float, int32, uint32, bool

GetDouble(...) — accepts double, float, int32, uint32, int64, uint64, bool

GetString(...) — accepts any type (falls back to string representation)

GetBool(...) — accepts bool only

Temporal columns (date, timestamp, interval) are not exposed as dedicated typed objects. Use GetString(...) for their canonical string form (e.g. "1970-01-01"), and GetInt64(...) to read the raw epoch value of date / timestamp columns.

Metadata

ColumnCount() const

Get the number of columns.

ColumnNames() const

Get column names from schema.

Other Methods

ToString() const

Convert entire result set to string.

GetCurrentRowAsString() const

Convert the current cursor row to a human-readable, comma-separated string (NULL cells render as null). Handy for printing rows while iterating with hasNext() / next(). Throws if the cursor is past the end of the result set.

length() const

Get total number of rows.

result_schema() const

Get result schema metadata.

response() const

Get underlying protobuf response (const reference).

shared_response() const

Get shared ownership of the underlying protobuf response.

Useful when callers need to extend the lifetime of the response beyond the QueryResult (e.g. zero-copy Arrow export).

Serialize() const

Serialize entire result set to string.

Example

auto result = QueryResult::From(serialized);
 
// Access by column index
while (result.hasNext()) {
    if (!result.IsNull(0)) {
        int32_t id = result.GetInt32(0);
        std::string name = result.GetString(1);
    }
    result.next();
}
 
// Access by column name
result.Reset();
while (result.hasNext()) {
    if (!result.IsNull("id")) {
        int32_t id = result.GetInt32("id");
        std::string name = result.GetString("name");
        double score = result.GetDouble("score");
    }
    result.next();
}