#include <stdio.h>
#include <stdlib.h>
#include <mysql.h>

int main(int argc, char *argv[])
{

  MYSQL *conn;         // connection to MySQL server
  MYSQL_STMT *stmt;    // data structure for the prepared statement
  MYSQL_BIND bind[3]; // description of the parameters
  char *update =   "UPDATE Roles  SET name=? , description=?  WHERE RoleId=?";
  char name_buf[32];
  char description_buf[256];
  unsigned long name_len, description_len;
  int roleId;
    int roleId_is_null;

// connection to MySQL
conn = mysql_init(NULL);
mysql_options(conn, MYSQL_READ_DEFAULT_FILE, "");
if(mysql_real_connect(
      conn, hostName, userName, passwd,
      dbName, PortNumber,UnixSocketName,Flags) == NULL) {
    fprintf(stderr, "sorry, no database connection ...\n");
    return 1;
  }

// create statement structure
stmt = mysql_stmt_init(conn);
// initialize prepared statement
mysql_stmt_prepare(stmt, update, strlen(update));
// define parameters of the prepared statement
memset(bind, 0, sizeof(bind));
bind[0].buffer_type    = FIELD_TYPE_VAR_STRING;
bind[0].buffer         = name_buf;
bind[0].buffer_length = 32;
bind[0].length         = &name_len;
bind[1].buffer_type    = FIELD_TYPE_VAR_STRING;
bind[1].buffer         = description_buf;
bind[1].buffer_length  = 256;
bind[1].length         = &description_len;
bind[2].buffer_type    = FIELD_TYPE_LONG;
bind[2].buffer         = (gptr) &roleId;
bind[2].is_null        = &roleId_is_null;

mysql_stmt_bind_param(stmt, bind);
// execute command for the first time
strcpy(name_buf, "roleName");
name_len = strlen(name_buf);
strcpy(description_buf, "test prepared statements");
description_len = strlen(description_buf);
roleId=1;
roleId_is_null = 0;

int error=mysql_stmt_execute(stmt);
if(error){
    printf("error occur: %s\n",mysql_error(conn));
    exit(1);
}
/*
printf("new title with titleId=%d has been inserted\n",
       (int) mysql_insert_id(conn));
*/
printf("%d rows affected \n",mysql_affected_rows(conn));

// close statement and connection
mysql_stmt_close(stmt);
mysql_close(conn);
return 0;
}

 INSERTING: char *insert =   "INSERT INTO Roles (RoleId,Name,Description) VALUES(?,?,?)";
 UPDATING: char *delete =   "DELETE FROM Roles WHERE RoleId=?";