Невозможно найти строковый литерал оператора 'operator''conteudo' с аргументами 'const char [43]', 'unsigned int' ⇐ C++

[Anonymous]

У меня возникла проблема с отправкой данных о переменной в базу данных MySQL. Проблема в том, что я пытаюсь отправить данные RFID с переменной.
String INSERT_SQL ="INSERT INTO database.table VALUES('0 ',"conteudo")";

Выдает эту ошибку.
unable to find string literal operator 'operator""conteudo' with 'const char [43]', 'unsigned int' arguments
Вот полный код.
#include
#include
#include
#include
#include

Servo servo;

#define SS_PIN 21
#define RST_PIN 22

MFRC522 mfrc522(SS_PIN, RST_PIN);

const char* ssid = "";
const char* password = "";

char user[] = "";
char passw[] = "";

String conteudo = "";

#define MYSQL_DEBUG_PORT Serial

#define MYSQL_LOGLEVEL 0

#define USING_HOST_NAME true

#if USING_HOST_NAME

char server[] = "";
char default_database[] = "";
char default_table[] = "";

#else

IPAddress server(192, 168, 0, 250);
#endif

uint16_t server_port = 3306;

MySQL_Connection conn((Client *)&client);
MySQL_Query *query_mem;

int led_CH1 = 14;
int pos = 0;

void setup()
{
pinMode(led_CH1, OUTPUT);

Serial.begin(115200);

while (!Serial && millis() < 5000);

SPI.begin();

iniciarWiFi();

MYSQL_DISPLAY1("Connecting to", ssid);
MYSQL_DISPLAY3("Connecting to SQL Server @", server, ", Port =", server_port);
MYSQL_DISPLAY5("User =", user, ", PW =", passw, ", DB =", default_database);

mfrc522.PCD_Init();

servo.attach(25);
servo.write(100);

Serial.println("Aproxime o seu cartao do leitor...");
Serial.println();
}

void loop()
{

if ( ! mfrc522.PICC_IsNewCardPresent())
{
return;
}
if ( ! mfrc522.PICC_ReadCardSerial())
{
return;
}

Serial.print("UID da tag :");

byte letra;
for (byte i = 0; i < mfrc522.uid.size; i++)
{
Serial.print(mfrc522.uid.uidByte < 0x10 ? " 0" : " ");
Serial.print(mfrc522.uid.uidByte, HEX);
conteudo.concat(String(mfrc522.uid.uidByte < 0x10 ? " 0" : " "));
conteudo.concat(String(mfrc522.uid.uidByte, HEX));
}
Serial.println();
Serial.print("Mensagem : ");
conteudo.toUpperCase();

if (conteudo.substring(1) == "B0 21 A4 39")
{
digitalWrite(led_CH1, HIGH);
Serial.println("Cartao1 - Acesso concedido!");
Serial.println();

String INSERT_SQL ="INSERT INTO database.table VALUES('0 ',"conteudo")";

if (conn.connectNonBlocking(server, server_port, user, passw) != RESULT_FAIL)
{
delay(500);
runInsert();
conn.close(); // close the connection
}
else
{
MYSQL_DISPLAY("\nConnect failed. Trying again on next iteration.");
}

delay(100);

delay(3000);
for (pos = 0; pos = 0; pos -= 1) { // goes from 180 degrees to 0 degrees
servo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}
digitalWrite(led_CH1, LOW);

}

if (conteudo.substring(1) != "B0 21 A4 39")
{
Serial.println("Cartao2 - Acesso negado !!");
Serial.println();
}
delay(1000);
}
void iniciarWiFi() {
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
Serial.print("A conectar ao WiFi .");
while (WiFi.status() != WL_CONNECTED)
{
Serial.print('.');
delay(1000);
}
Serial.println(WiFi.localIP());
}

void runInsert()
{
// Initiate the query class instance
MySQL_Query query_mem = MySQL_Query(&conn);

if (conn.connected())
{
MYSQL_DISPLAY(INSERT_SQL);

// Execute the query
// KH, check if valid before fetching
if ( !query_mem.execute(INSERT_SQL.c_str()) )
{
MYSQL_DISPLAY("Insert error");
}
else
{
MYSQL_DISPLAY("Data Inserted.");
}
}
else
{
MYSQL_DISPLAY("Disconnected from Server. Can't insert.");
}
}


Подробнее здесь: https://stackoverflow.com/questions/726 ... st-char-43