How to use the C++ API's prepared statement with parameters?

[b3n-h4il]

This page in the docs talks about prepared statements, which are, as I understand it, a way to run a Cypher statement that is a query we pass arguments to. Well, I need that function in my C++ application, but I'm having trouble figuring out how to implement it.
I'm tring to use auto result {connection->executeWithParams(PreparedStatement *preparedStatement, std::unordered_map<std::string, std::unique_ptr<common::Value>> inputParams)}, but when I give it the std::unordered_map it's asking I get an error sayng that 'there isn't a funcion compatible with the arguments I'm passing'. I've created the map executeWithParams needs like this: std::unordered_map<std::string, std::unique_ptr<kuzu::common::Value>> inputParams { {"name", make_unique<kuzu::common::Value>(parameterName)} };. But I keep getting an error about not finding a compatible function to the parameters I'm passing, and I can't find a usage example in C++. Can someone help me?

[mewim]

Hi @b3n-h4il,

You can follow how it is done in our C-API binding: https://github.com/kuzudb/kuzu/blob/master/src/c_api/prepared_statement.cpp

[mewim]

Here is a concrete example:

#include "kuzu.hpp"
#include <iostream>
using namespace kuzu::main;
using namespace kuzu::common;

int main(int argc, char **argv)
{
   auto database = std::make_unique<Database>(":memory:", SystemConfig());
   auto connection = std::make_unique<Connection>(database.get());
   auto query = "RETURN $1, $2, $3";
   std::unordered_map<std::string, std::unique_ptr<Value>> params;
   params["1"] = std::make_unique<Value>(int64_t(1));
   params["2"] = std::make_unique<Value>(float(3.14159));
   params["3"] = std::make_unique<Value>(std::string("Hello, World!"));

   auto prepared_statement = connection->prepare(query);
   auto result = connection->executeWithParams(prepared_statement.get(), std::move(params));
   if (result->isSuccess()) {
       std::cout << "Query executed successfully!" << std::endl;
   } else {
       std::cout << "Query execution failed: " << result->getErrorMessage() << std::endl;
   }
   auto result_string = result->toString();
   std::cout << "Result: " << result_string << std::endl;
   return 0;
}

This should print:

Query executed successfully!
Result: $1|$2|$3
1|3.141590|Hello, World!