reading sqlite database via mqtt to an mqtt broker using c - c

Question

I want to read a sqlite3 db file for sending data from an embedded device over a data connection via mqtt to an mqtt broker in c language.
i m getting error "Failed to connect, return code 5"
can anyone please help me out for correcting this code
thanks in advance
#include <stdlib.h>
#include <string.h>
#include <MQTTClient.h>
#include <sqlite3.h>
#define ADDRESS "tcp:localhost:1883"
#define CLIENTID "......"
#define USERNAME "....."
#define PASSWORD "....."
#define TOPIC "..."
#define QOS 1
#define TIMEOUT 10000L
static int callback(void *NotUsed, int argc, char* argv[],char **azColName)
{
int i;
for(i = 0; i<argc; i++) {
printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
}
}
int main() {
int rc;
MQTTClient client;
MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
MQTTClient_message pubmsg = MQTTClient_message_initializer;
MQTTClient_deliveryToken token;
MQTTClient_create(&client, ADDRESS, CLIENTID,
MQTTCLIENT_PERSISTENCE_NONE, NULL);
conn_opts.username = USERNAME;
conn_opts.password = PASSWORD;
conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to connect, return code %d\n", rc);
exit(EXIT_FAILURE);
}
pubmsg.qos = QOS;
pubmsg.retained = 0;
sqlite3 *db;
char *zErrMsg = 0;
char *sql;
const char* data = "Callback function called";
rc = sqlite3_open("db/dht.db", &db);
sql = "SELECT * from table";
rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg);
MQTTClient_publishMessage(client, TOPIC, &pubmsg, &token);
printf("Waiting for up to %d seconds for publication of %s\n"
"on topic %s for client with ClientID: \n",
(int)(TIMEOUT/1000), TOPIC, CLIENTID);
rc = MQTTClient_waitForCompletion(client, token, TIMEOUT);
printf("Message with delivery token %d delivered\n", token);
sqlite3_close(db);
return 0 ;
}

Answer 1

From the Paho C doc
MQTTClient_connect()
int MQTTClient_connect(MQTTClient handle, MQTTClient_connectOptions* options)
This function attempts to connect a previously-created client (see
MQTTClient_create()) to an MQTT server using the specified options. If
you want to enable asynchronous message and status notifications, you
must call MQTTClient_setCallbacks() prior to MQTTClient_connect().
Parameters
handle A valid client handle from a successful call to MQTTClient_create().
options A pointer to a valid MQTTClient_connectOptions structure.
Returns
MQTTCLIENT_SUCCESS if the client successfully connects to the server.
An error code is returned if the client was unable to connect to the
server. Error codes greater than 0 are returned by the MQTT protocol:
1: Connection refused: Unacceptable protocol version
2: Connection refused: Identifier rejected
3: Connection refused: Server unavailable
4: Connection refused: Bad user name or password
5: Connection refused: Not authorized
6-255: Reserved for future use
A return code of 5 means "Not authorized", this implies your username/password are wrong.