QueryResults

This class holds the column-based result data returned by a Query() call. Access it via Results() on a QueryResponse object.

const QueryResults& results = response.Results();

METHODS:

• FieldDataPtr OutputField(const std::string& name) const

  Returns the named output field as a FieldDataPtr. Cast to the concrete type with std::dynamic_pointer_cast<Int64FieldData>(results.OutputField("id")).

• const std::vector<FieldDataPtr>& OutputFields() const

  Returns all output fields in the order they were returned by the server.

• const std::set<std::string>& OutputFieldNames() const

  Returns the set of output field names that were requested in the query.

• Status OutputRows(EntityRows& rows) const

  Converts all result rows to a vector of JSON-like row maps and stores them in rows.

• Status OutputRow(int i, EntityRow& row) const

  Converts the row at index i to a JSON-like row map.

• uint64_t GetRowCount() const

  Number of rows returned. When the query uses count(*), this returns the aggregate count.

Example

#include <milvus/MilvusClientV2.h>
using namespace milvus;

auto client = MilvusClientV2::Create();
client->Connect(ConnectParam("http://localhost:19530").WithToken("root:Milvus"));

QueryResponse response;
auto status = client->Query(
    QueryRequest()
        .WithCollectionName("my_collection")
        .WithFilter("age > 20")
        .AddOutputField("id")
        .AddOutputField("age")
        .AddOutputField("vec"),
    response);
if (!status.IsOk()) {
    std::cout << status.Message() << std::endl;
}

const QueryResults& results = response.Results();
auto id_field  = std::dynamic_pointer_cast<Int64FieldData>(results.OutputField("id"));
auto age_field = std::dynamic_pointer_cast<Int32FieldData>(results.OutputField("age"));
std::cout << "Rows: " << results.GetRowCount() << "\n";
for (size_t i = 0; i < results.GetRowCount(); ++i) {
    std::cout << "  id=" << id_field->Value(i)
              << " age=" << age_field->Value(i) << "\n";
}