First step to do any operation is to create a Manager instance.

// Connect to MongoDB using Manager Instance
$manager = new MongoDBDriverManager("mongodb://localhost:27017");

Second step is to prepare and execute a command on a database to show the list of databases available.

// Create a Command Instance
$databaseList = new MongoDBDriverCommand(["listDatabases" => 1]);

// Execute the command on the database
$cursor = $manager->executeCommand("admin", $databaseList);

Example

Try the following example to list databases available by default in MongoDB server −

Copy and paste the following example as mongodb_example.php −

<?php
   try {
      // connect to mongodb
      $manager = new MongoDBDriverManager("mongodb://localhost:27017");

      // Create a Command Instance
      $databaseList = new MongoDBDriverCommand(["listDatabases" => 1]);

      // Execute the command on the database
      $cursor = $manager->executeCommand("admin", $databaseList);
   
      $databases = current($cursor->toArray());
   
      foreach ($databases->databases as $database) {    
         echo $database->name . "<br/>";
      }
   } catch (MongoDBDriverExceptionException $e) {	   
      echo "Exception:", $e->getMessage(), "n";
   }
?>

Output

Access the mongodb_example.php deployed on apache web server and verify the output.

admin
config
local