Sending sensor data to a MySQL server with Arduino and Sim900a - arduino

Question

I am trying to send sensor data to a MySQL server of mine but can't achieve that. I followed several similar examples here in other questions but it isn't working. The Arduino code is given below. The idea is to measure the voltage and current across a load and send it to a MySQL server. TIA.
#include <SoftwareSerial.h>
SoftwareSerial gprsSerial(7, 8);
//variables that imitates actual voltage and current data
float a=random(300.0);
float b=random(2.00);
char c[10]="B110";
void setup() {
gprsSerial.begin(19200);
Serial.begin(19200);
Serial.println("Config SIM900A...");
delay(2000);`enter code here`
Serial.println("Done!...");
gprsSerial.flush();
Serial.flush();
// attach or detach from GPRS service
gprsSerial.println("AT+CGATT?");
delay(100);
toSerial();
// bearer settings
gprsSerial.println("AT+SAPBR=3,1,\"CONTYPE\",\"GPRS\"");
delay(2000);
toSerial();
// bearer settings
gprsSerial.println("AT+SAPBR=3,1,\"APN\",\"my carrier apn here\"");
delay(2000);
toSerial();
// bearer settings
gprsSerial.println("AT+SAPBR=1,1");
delay(2000);
toSerial();
}
void loop() {
// initialize http service
gprsSerial.println("AT+HTTPINIT");
delay(2000);
toSerial();
// set http param value
gprsSerial.println("AT+HTTPPARA=\"URL\",\"http://mocdl.net/api/data/create?voltage="" + a + ""&current="" + b + "" &load_id="" + c + ""\"");
delay(2000);
toSerial();
// set http action type 0 = GET, 1 = POST, 2 = HEAD
gprsSerial.println("AT+HTTPACTION=0");
delay(6000);
toSerial();
// read server response
gprsSerial.println("AT+HTTPREAD");
delay(1000);
toSerial();
gprsSerial.println("");
gprsSerial.println("AT+HTTPTERM");
toSerial();
delay(300);
gprsSerial.println("");
delay(10000);
}
void toSerial() {
while(gprsSerial.available()!=0) {
Serial.write(gprsSerial.read());
}
}

Answer 1

As Panciz said you should set you APN (i think you already know that).
You should also make a small change in your program.
gprsSerial.println("AT+HTTPPARA=\"URL\",\"http://mocdl.net/api/data/create?voltage="" + a + ""&current="" + b + "" &load_id="" + c + ""\"");
The above line wont work as you expected.
So edit the http request line as follows :
gprsSerial.println("AT+HTTPPARA=\"URL\",\"http://mocdl.net/api/data/create?voltage=%f&current=%f&load_id=%f\"",a,b,c);

Answer 2

You must set your APN.
For example in my case I need to add
mySerial.println("AT+SAPBR=3,1,\"APN\",\"internet\"")