Counting Columns with the columnCount() Method

The columnCount() method returns the number of columns in the result set prepared by the statement. This is extremely useful when writing generic data display functions where you do not know in advance how many columns the query will return. The method works directly on the prepared statement object after its execution.

EXAMPLE

<?php
class Database {
    private $server = "localhost";
    private $username = "root";
    private $password = "";
    private $db_name = "pdo_db";
    public $connection;

    public function __construct() {
        try {
            // Added charset=utf8mb4 for character support
            $dsn = "mysql:host=" . $this->server . ";dbname=" . $this->db_name . ";charset=utf8mb4";
            $this->connection = new PDO($dsn, $this->username, $this->password);
            $this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        } catch(PDOException $e) {
            die("Connection failed: " . $e->getMessage());
        }
    }

    public function getColumnCount($table) {
        $statement = $this->connection->prepare("SELECT * FROM $table LIMIT 1");
        $statement->execute();
        
        // The method returns the number of columns in the result
        $count = $statement->columnCount();
        
        $statement->closeCursor();
        return $count;
    }
}

// PART 3: Usage
$db = new Database();
$col_count = $db->getColumnCount('users');

echo "Table users contains " . $col_count . " columns.";
?>

RESULT

The result will be displayed here...

Practical Application: The columnCount method is used when building dynamic reports or when you want to verify if the query returned the expected number of data fields. Check the process at home by following these steps:

Start the Apache and MySQL modules in the XAMPP control panel.
Via phpMyAdmin, ensure that the pdo_db database and the users table with records exist.
The method returns an integer representing the number of columns in the prepared statement.
Insert the example below into your PHP file and observe the column count output in your browser.