I learned about StringStream today at work,

#include <iostream>
#include <sstream>
#include <stdio.h>
#include <string.h>

using namespace std;

char* getSql() {
    float outdoorTempInC = 15;
    int outoorHumidity = 23;
    float indorTempinC = 20;
    int humidity = 22;
    int val = 400; // soil sensor reading
    int avgVal = 38; // avaerage of 10 values of soils sensor
    char statusMsg[50] = {"Hello World"} ;
    std::stringstream sqlQuery;
    sqlQuery  << "INSERT INTO arduinoSensorData.sensorLog (out_temperature,  " 
        << "out_humidity,  drwngRoom_temperature, drwngRoom_humidity, "
        << "pot1_soilMoisture, pot1_avg_SoilMoisture, wateringPot1) VALUES ('" 
        << outdoorTempInC << "', '" << outoorHumidity << "', '" << indorTempinC
        << "', '" << humidity << "', '" << val << "', '" << avgVal << "', '"
        << statusMsg << "');";
        
    char *mychar = new char[sqlQuery.str().length() + 1];
    strcpy(mychar, sqlQuery.str().c_str());
    return mychar;
}

string getSqlStream() {
    float outdoorTempInC = 15;
    int outoorHumidity = 23;
    float indorTempinC = 20;
    int humidity = 22;
    int val = 400; // soil sensor reading
    int avgVal = 38; // avaerage of 10 values of soils sensor
    char statusMsg[50] = {"Hello World"} ;
    std::stringstream sqlQuery;
    sqlQuery  << "INSERT INTO arduinoSensorData.sensorLog (out_temperature,  " 
        << "out_humidity,  drwngRoom_temperature, drwngRoom_humidity, "
        << "pot1_soilMoisture, pot1_avg_SoilMoisture, wateringPot1) VALUES ('" 
        << outdoorTempInC << "', '" << outoorHumidity << "', '" << indorTempinC
        << "', '" << humidity << "', '" << val << "', '" << avgVal << "', '"
        << statusMsg << "');";
        
    return sqlQuery.str();
}

int main()
 {
    string sql = getSqlStream();
    cout << getSql() << "\n";
    cout << sql.c_str() << "\n";
    return  0;
}

I was very happy until I discovered I cannot use StringStream in arduino, so I dug in the internet and came across with this

https://gist.github.com/cmaglie/5883185

so if I try to use the above linked gist StringSteam like I have used in my above example code I am getting this error:

Or I am doing it completely the wrong way it feels I still cannot use it the way I i have done in example , please help.

I learned about StringStream today at work.

#include <iostream>
#include <sstream>
#include <stdio.h>
#include <string.h>

using namespace std;

char* getSql() {
    float outdoorTempInC = 15;
    int outoorHumidity = 23;
    float indorTempinC = 20;
    int humidity = 22;
    int val = 400; // soil sensor reading
    int avgVal = 38; // avaerage of 10 values of soils sensor
    char statusMsg[50] = {"Hello World"} ;
    std::stringstream sqlQuery;
    sqlQuery  << "INSERT INTO arduinoSensorData.sensorLog (out_temperature,  " 
        << "out_humidity,  drwngRoom_temperature, drwngRoom_humidity, "
        << "pot1_soilMoisture, pot1_avg_SoilMoisture, wateringPot1) VALUES ('" 
        << outdoorTempInC << "', '" << outoorHumidity << "', '" << indorTempinC
        << "', '" << humidity << "', '" << val << "', '" << avgVal << "', '"
        << statusMsg << "');";
        
    char *mychar = new char[sqlQuery.str().length() + 1];
    strcpy(mychar, sqlQuery.str().c_str());
    return mychar;
}

string getSqlStream() {
    float outdoorTempInC = 15;
    int outoorHumidity = 23;
    float indorTempinC = 20;
    int humidity = 22;
    int val = 400; // soil sensor reading
    int avgVal = 38; // avaerage of 10 values of soils sensor
    char statusMsg[50] = {"Hello World"} ;
    std::stringstream sqlQuery;
    sqlQuery  << "INSERT INTO arduinoSensorData.sensorLog (out_temperature,  " 
        << "out_humidity,  drwngRoom_temperature, drwngRoom_humidity, "
        << "pot1_soilMoisture, pot1_avg_SoilMoisture, wateringPot1) VALUES ('" 
        << outdoorTempInC << "', '" << outoorHumidity << "', '" << indorTempinC
        << "', '" << humidity << "', '" << val << "', '" << avgVal << "', '"
        << statusMsg << "');";
    return sqlQuery.str();
}

int main() {
    string sql = getSqlStream();
    cout << getSql() << "\n";
    cout << sql.c_str() << "\n";
    return  0;
}

I was very happy until I discovered I cannot use StringStream in Arduino, so I dug in the internet and came across with this.

So if I try to use the above linked gist StringSteam like I have used in my example code, I am getting this error:

Or I am doing it completely the wrong way? It feels I still cannot use it the way I have done in the example. Please help.