samples/ydb_service/views/select-rows/post/view.cpp

#include "view.hpp"
 
#include <fmt/format.h>
 
#include <userver/formats/json.hpp>
#include <userver/logging/log.hpp>
#include <userver/utils/datetime.hpp>
 
#include <userver/ydb/component.hpp>
#include <userver/ydb/table.hpp>
 
namespace sample {

formats::json::Value SelectRowsHandler::
    HandleRequestJsonThrow(const server::http::HttpRequest& request, const formats::json::Value& request_json, server::request::RequestContext&)
        const {
    request.GetHttpResponse().SetContentType(http::content_type::kApplicationJson);
    const ydb::OperationSettings query_params = {
        3,                                // retries
        std::chrono::milliseconds(1100),  // client_timeout
        ydb::TransactionMode::kStaleRO
    };
    static const ydb::Query kSelectQuery = {
        "--!syntax_v1\n"
        "DECLARE $service_key AS String;"
        "DECLARE $channel_keys AS List<Int64>;"
        "DECLARE $created_key AS Timestamp;"
        "SELECT id, name, service, channel, created, state "
        "FROM events VIEW sample_index "
        "WHERE service = $service_key AND channel IN $channel_keys "
        "AND created > $created_key;",
        ydb::Query::NameLiteral("select"),
        ydb::Query::LogMode::kNameOnly,
    };
 
    auto response = Ydb().ExecuteDataQuery(
        query_params,
        kSelectQuery,  //
        "$service_key",
        request_json["service"].As<std::string>(),  //
        "$channel_keys",
        request_json["channels"].As<std::vector<int64_t>>(),  //
        "$created_key",
        request_json["created"].As<std::chrono::system_clock::time_point>()
    );
 
    if (response.GetCursorCount() != 1) {
        throw std::runtime_error("Unexpected response data");
    }
 
    formats::json::ValueBuilder items_builder(formats::json::Type::kArray);
    for (auto row : response.GetSingleCursor()) {
        formats::json::ValueBuilder item;
        item["id"] = row.Get<std::string>("id");
        item["name"] = row.Get<ydb::Utf8>("name").GetUnderlying();
        item["service"] = row.Get<std::string>("service");
        item["channel"] = row.Get<std::int64_t>("channel");
        item["created"] = row.Get<std::chrono::system_clock::time_point>("created");
 
        auto state = row.Get<std::optional<formats::json::Value>>("state");
        if (state) {
            item["state"] = std::move(*state);
        }
 
        items_builder.PushBack(item.ExtractValue());
    }
 
    return formats::json::MakeObject("items", items_builder.ExtractValue());
}
 
}  // namespace sample