Chapter 6 ■ Building low-Cost MysQl data nodes
Listing 6-5. “Hello, MySQL!” Sketch
/**
- Example: Hello, MySQL!
- This code module demonstrates how to create a simple database-enabled
- sketch.
*/
#include <Ethernet.h>
#include <MySQL_Connection.h>
#include <MySQL_Cursor.h>
/ Setup for Ethernet Library /
byte mac_addr[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress server_addr(10, 0, 1, 23); // The IP address of your database server
/ Setup for the Connector/Arduino /
EthernetClient client;
MySQL_Connection conn((Client *)&client);
char user[] = "root";
char password[] = "secret";
char INSERT_SQL[] = "INSERT INTO test_arduino.hello VALUES ('Hello from Arduino!', NULL)";
void setup() {
Ethernet.begin(mac_addr);
Serial.begin(115200);
while (!Serial);
Serial.println("Connecting...");
if (conn.connect(server_addr, 3306, user, password))
{
delay(500);
/ Write Hello, World to MySQL table test_arduino.hello /
// Initiate the query class instance
MySQL_Cursor *cur_mem = new MySQL_Cursor(&conn);
// Execute the query
cur_mem->execute(INSERT_SQL);
delete cur_mem;
Serial.println("Query Success!");
}
else
Serial.println("Connection failed.");
}
void loop() {
}
Before you click the button to compile and upload the sketch, let’s discuss a couple of errors that could
occur. If you have the wrong IP address or the wrong username and password for the MySQL server, you
could see a connection failure in the serial monitor like that shown in Figure 6-14.