Question 63688 in PhpMyAdmin Question posted in
The official documentation can be found here.

creating a databased after checking it doesn't exist in PHP – Phpmyadmin

I have this code however, when the database already exists, I get an empty response and echo doesn’t show anything:

try
{
    //die('here');

    $conn = new PDO("mysql:host=$host", $username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    if (!PDO_select_db($conn, $dbName)){
      echo "Database doesn't exist!";
      $sql = "CREATE DATABASE ".$dbName;
      if ($conn->query($sql) === TRUE) {
        echo "Database was created successfully";
      } else {
        echo "Error creating database: " . $conn->error;
      }

  } 
  else {
  echo "Database already exists!";
  }
}

What is wrong with this code?

As you see, using Firefox Inspect, in Network tab, I see No response data available for this request.
enter image description here

Expected behavior: since the database already exists, I am expecting to see Database already exists! in the Response section of Network tab.

So, my database, named judges, exists and using $ php -l submit.php I see that my code has no error.
I can also see this in phpMyAdmin GUI:
enter image description here

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    Turns out I am using a new version of PHP and the functions I was using were obsolete.

    The code below works:

    $host = "localhost";
$username = "root";
$password = "";
$dbName = "judges";

try
{

  $conn = new mysqli($host, $username, $password);
  if ($conn->connect_error) {
      die("Connection failed: " . $conn->connect_error);
  }

  // If database is not exist create one
  if (!mysqli_select_db($conn,$dbName)){
      $sql = "CREATE DATABASE ".$dbName;
      if ($conn->query($sql) === TRUE) {
          echo "Database created successfully";
      }else {
          echo "Error creating database: " . $conn->error;
      }
  } 


}
catch(PDOException $e)
{
    echo "in catch block";
    echo "Connection failed: " . $e->getMessage();
    echo $sql . "<br>" . $e->getMessage();
}

  2. 0

    The easiest way to use a database in PDO is to name it in the DSN when you connect:

    $conn = new PDO("mysql:host=$host;dbname=name_of_db", $username, $password);

    If you want to change the default database, you can use PDO::exec() to run a USE <database> statement:

    $conn->exec("USE name_of_db");

    You can’t use mysql_select_db() because all the mysql_* functions were deprecated in PHP 5.5 (circa 2013), and removed from PHP in version 7.0 (2015). You should use more current resources to learn PHP and PDO.

    PS:
    Honestly, I don’t add CREATE DATABASE to my application code. The database just better exist. If it doesn’t, references to it will throw an exception, so I create the database manually before I deploy my application. Since that needs to happen only once, it’s a waste of time and lines of code to check that the database exists during every PHP request.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search