Response to '[PHP] mysql_connect noob question' on php-general@lists.php.net

dbcred_form.php

<?php

error_reporting(-1);
ini_set('display_errors',1);
ini_set('display_startup_errors',1);

echo '<h1>$_POST:</h1>'.PHP_EOL;
echo '<pre><code>'.PHP_EOL;
echo htmlspecialchars(print_r($_POST,true));
echo '</code></pre>'.PHP_EOL;


if (isset($_POST['submit'])) {


  $dbuser = (isset($_POST['user']) && !empty($_POST['user'])) ? $_POST['user'] : null;
  $dbpass = (isset($_POST['pass']) && !empty($_POST['pass'])) ? $_POST['pass'] : null;
  $dbname = 'test001';
  $host = 'localhost';

  $db = new mysqli($host, $dbuser, $dbpass, $dbname);
  if ($db->connect_error) {
    echo '<pre><code>Connect Error: '. $db->connect_errno.': '.$db->connect_error.'</code></pre>'.PHP_EOL;
  } else {
    echo '<p>Connected!</p>'.PHP_EOL;
  }
}

?>
<form method="post">
Enter user/pw for data base: 
<label for="user">User:</label><input name="user" type="text" value="" />
<label for="pass">Pass:</label><input name="pass" type="text" value="" />
<input type="submit" name="submit" value="Log in" />
</form>

grant.sql

grant select on test001.* to 'cheapuser'@'localhost' identified by 'secret';

links to output screenshots

http://db.tt/MiTbG7gx - successful login
http://db.tt/DKMnP4vs - unsuccessful login

test001.sql

-- MySQL dump 10.13  Distrib 5.5.29, for debian-linux-gnu (i686)
--
-- Host: localhost    Database: test001
-- ------------------------------------------------------
-- Server version	5.5.29-0ubuntu0.12.04.2

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

--
-- Table structure for table `table1`
--

DROP TABLE IF EXISTS `table1`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `table1` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Dumping data for table `table1`
--

LOCK TABLES `table1` WRITE;
/*!40000 ALTER TABLE `table1` DISABLE KEYS */;
INSERT INTO `table1` VALUES (1,'bob'),(2,'ted'),(3,'carol'),(4,'alice');
/*!40000 ALTER TABLE `table1` ENABLE KEYS */;
UNLOCK TABLES;
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

-- Dump completed on 2013-04-21 10:26:47